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Am J Physiol Heart Circ Physiol 291: H45-H51, 2006. First published January 6, 2006; doi:10.1152/ajpheart.00939.2005
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TRANSLATIONAL PHYSIOLOGY

Evidence for histamine as a neurotransmitter in the cardiac sympathetic nervous system

Mingkai Li,1 Jing Hu,1 Zhong Chen,2 Jia Meng,1 Haifang Wang,1 Xue Ma,1 and Xiaoxing Luo1

1Department of Pharmacology, The Fourth Military Medical University, Xi'an; and 2Department of Pharmacology, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China

Submitted 1 September 2005 ; accepted in final form 4 January 2006


   ABSTRACT
TOP
 ABSTRACT
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 
The colocalization of histamine (HA) and norepinephrine (NE) immunoreactivities was identified within the superior cervical ganglia neurons of the guinea pig. HA and NE immunoreactivity levels were significantly attenuated after chemical sympathectomy with 6-hydroxydopamine (6-OHDA). Coexistence of NE and HA was also visualized in the cardiac sympathetic axon and varicosities labeled with anterograde tracer biotinylated dextran amine. Depolarization of cardiac sympathetic nerve endings (synaptosomes) with 50 mM potassium stimulated endogenous HA release, which was significantly attenuated by 6-OHDA or a vesicular monoamine transporter 2 (VMAT2) inhibitor reserpine pretreatments. Compound 48/80, a mast cell releaser, did not affect cardiac synaptosome HA exocytosis. Furthermore, K+-evoked HA release was abolished by the N-type Ca2+-channel blocker {omega}-conotoxin but was not affected by the L-type Ca2+-channel blocker lacidipine. Cardiac synaptosome HA exocytosis was augmented by the enhanced synthesis of HA or the inhibition of HA metabolism. HA H3-receptor activation by (R)-{alpha}-methylhistamine inhibited high K+-evoked histamine release. The HA H3 receptor antagonist thioperamide enhanced K+-evoked HA release and blocked the (R)-{alpha}-methylhistamine effect. The K+-evoked endogenous NE release was attenuated by preloading the cardiac synaptosomes with L-histidine or quinacrine. These inhibitory effects were reversed by thioperamide or antagonized by {alpha}-fluoromethylhistidine. Our findings indicate that high K+-evoked corelease of NE and HA may be inhibited by endogenous HA via activation of presynaptic HA H3-receptors. The H3-receptor may function as an autoreceptor, rather than a heteroreceptor, in the regulation of sympathetic neurotransmission and HA may be a novel sympathetic neurotransmitter.

histamine H3 receptor; sympathetic nerve; heart

IT HAS BEEN WELL DOCUMENTED that peripheral histamine (HA) is not located exclusively in classic mast cells (10, 32, 44). It has also been demonstrated that HA is present within the mammalian enteric nervous system of the gut, celiac-superior mesenteric ganglion complex, superior cervical ganglion, and in sensory cells of the rat carotid body (11, 18, 27, 28). It has been observed that the superior cervical ganglia in mast cell-deficient mice contain HA (43). The release of HA from sympathetic nerve endings can be evoked by different stimuli (9, 20). However, it has not been established whether HA acts as a neurotransmitter in the peripheral nerve system.

Sympathetic nerve endings are endowed with a variety of cell-surface receptors. For example, autoinhibitory {alpha}2-adrenoceptors and HA H3 receptors modulate norepinephrine (NE) release from sympathetic nerves that innervate the cardiovascular system (3). Activation of {alpha}2-adrenoceptors or H3 receptors inhibits sympathetic neurotransmission (3, 19, 21, 38). The mast cell-released HA has been recognized as a modulator of afferent sensory C fibers and cholinergic neurotransmission (15, 26). Because little is known about the origin of the endogenous HA that activates presynaptic H3 receptors on sympathetic terminals, the H3 receptor on the adrenergic nerve terminals in cardiovascular tissues has been considered as an inhibitory heteroreceptor (6, 22, 31).

Previous studies have shown that histidine decarboxylase (HDC) is expressed in the superior cervical ganglion (SCG) of the guinea pig and that HA coexists with tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DbetaH) simultaneously in the SCG (20). It has also been observed that an efflux of endogenous HA from isolated guinea pig hearts or atria could be evoked by sympathetic nerve stimulation or electrical field stimulation (9, 20). The present study provides further direct evidence to demonstrate the coexistence of HA and NE within sympathetic neurons and reveals the modulation mechanisms of HA release from sympathetic terminals.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 
Adrenergic denervation with 6-hydroxydopamine or reserpine. All experiments and animal care procedures were reviewed and approved by the Animal Resource Center of the Fourth Military Medical University. Male guinea pigs weighing 300–400 g were injected intravenously with 50 mg/kg of 6-hydroxydopamine (6-OHDA), which was dissolved in saline containing 0.1% ascorbic acid on day 1 and 100 mg/kg of 6-OHDA on day 7. Control animals received injections of a solution containing 0.1% ascorbic acid in saline. The animals were euthanized on the seventh day after the last injection for experimental use. To determine the impact of the vesicular monoamine transporter 2 inhibitor reserpine on HA release, guinea pigs were given 2 mg/kg reserpine by intraperitoneal injection. The heart was isolated at 24 h after the injection.

Double immunofluorescence labeling of HA and NE. The animals were anesthetized with pentobarbital sodium (30 mg/kg ip) and then fixed by perfusion with 4% paraformaldehyde in 0.1 M phosphate buffer (PB). The SCG was removed, and 10 µm-thick sections were cut using a cryostat microtome (Leica Cryostatt 3000, Bensheim, Germany). The sections were incubated with a rabbit anti-HA antibody at 1:1,000 dilution and a mouse anti-NE monoclonal antibody at 1:1,000 dilution in PBS containing 0.01% Triton X-100 (PBS-T), simultaneously. Antibody incubations were conducted in a humid chamber at 4°C for 36 h. The slides were washed three times for 15 min with PBS-T and then incubated for 30 min at 37°C with the secondary antibodies donkey anti-mouse immunoglobulin conjugated with FITC at a dilution of 1:500 and goat anti-rabbit antibody conjugated with tetramethylrhodamine isothiocyanate (TMRITC) at a 1:500 dilution. The sections were washed three times for 15 min in PBS and mounted in PBS-glycerol (1:9 dilution). Rabbit anti-HA antibody was replaced with normal rabbit serum in control sections. Because the fixation procedure occasionally produces nonspecific fluorescence in tissues, the specificity of immunostaining was carefully compared with the control sections. The slides were examined with a laser confocal microscope (Olympus FV300, Olympus, Tokyo, Japan) under an excitation wavelength of 488 nm for HA and 543 nm for NE, respectively. Digital images were captured and analyzed by the Confocal Image Program.

Anterograde labeling. Guinea pigs were anesthetized with pentobarbitone (30 mg/kg ip) and then received unilateral pressure injections of the anterograde tracer biotinylated dextran amine (BDA) through micropipettes (tip diameter 15–25 µm) stereotaxically positioned into the SCG (29). After survival time of 3 days, the animals were deeply anesthetized with pentobarbitone and perfused through the ascending aorta with a mixture of 4% paraformaldehyde and 0.05% glutaraldehyde in 0.1 mol/l PB. The cardiac ventricle was removed, postfixed in the same fixative for 3 h, and stored in PB overnight. Then 10 µm-thick sections were cut using a cryostat microtome.

For double immunofluorescence labeling of BDA with HA or NE in the axon, the sections were incubated with a rabbit anti-HA antibody or mouse anti-NE monoclonal antibody at 1:1,000 dilution in PBS-T. Antibody incubations were conducted in a humid chamber at 4°C for 36 h. The slides were washed three times for 15 min with PBS-T and then incubated for 30 min at 37°C with the secondary antibodies Cy3-conjugated avidin and FITC-conjugated immunoglobulin at 1:500 dilutions. The sections were washed three times for 15 min in PBS and mounted in PBS-glycerol. Slides were examined with a laser confocal microscope under an excitation wavelength of 600 nm for BDA and 543 nm for HA or NE.

For triple immunofluorescence staining of BDA, HA, and NE in varicosities, the sections were incubated with anti-HA and anti-NE antibodies simultaneously and then followed by incubation with donkey anti-mouse immunoglobulin conjugated with FITC, goat anti-rabbit antibody conjugated with TMRITC, and avidin-Alexa Fluor 647 (1:200) for 30 min at 37°C. The sections were washed and mounted in PBS-glycerol (1:9 dilution) as mentioned above. Slides were examined with a laser confocal microscope under an excitation wavelength of 488 nm for HA, 543 nm for NE, and 680 nm for BDA, respectively. Digital images were captured and analyzed by the Confocal Image Program (40).

Preparation of cardiac synaptosomal fractions. Cardiac synaptosomes were prepared as previously described (1, 14, 33).

L-Histidine uptake. Guinea pig cardiac synaptosomal fractions were resuspended in HEPES-buffered saline (HBS) to a final concentration of 2–3 mg/ml. After a 5-min preincubation of the tissue at 37°C, L-histidine was added to the cardiac synaptosomal suspension to a final concentration of 1 µM (13). After a 20-min incubation at 37°C, the samples were centrifuged for 20 min (20,000 g at 4°C). The supernatants were aspirated, and the pellets were surface washed with 1 ml of HBS and resuspended in 500 µl HBS. Control values were obtained by running parallel samples treated with vehicle instead of L-histidine.

HA and NE release from cardiac synaptosomes. The release of HA or NE from cardiac synaptosomes was evoked by depolarization with a 5-min pulse of HBS containing 50 mM KCl in a water bath at 37°C. In the NE release experiment, 1 mM pargyline, a monoamine oxidase inhibitor, was added to HBS to protect the degradation of NE (30). In each experiment, one sample was untreated (control, background release) and the others were treated as the following: KCl alone, KCl plus drugs, or drugs alone. Treated samples were first incubated for 20 min with the specified agent and then with K+ for 5 min. When antagonists were used, samples were incubated with the antagonist for 20 min before incubation with the agonist. The controls were incubated without drugs for an equivalent length of time. At the end of incubation, each sample was centrifuged for 20 min (20,000 g at 4°C). The supernatant was assayed with a spectrofluorometer to determine HA and NE content (34, 42). The pellet was assayed for protein content by a Bradford protein assay method (7). When high concentrations of KCl were used to depolarize synaptosomes, osmolarity was held constant by adjusting the NaCl concentration.

Drugs and chemicals. HA and NE antibodies, Compound 48/80, HA, NE, R-({alpha})-methylhistamine, thioperamide, and lacidipine were purchased from Sigma-Aldrich (St. Louis, MO). FITC and TMRITC conjugated secondary antibodies were obtained from Jackson Immuno Research (West Grove, PA). BDA and avidin-Alexa Fluo 647 were purchased from Molecular Probes (Eugene, OR). L-Histidine was purchased from Beijing Chemistry (Beijing, China). Reserpine was purchased from Jiangmen Pharmaceutical (Jiangmen, China). {omega}-Conotoxin ({omega}-CTX) was purchased from Peptide Institute (Osaka, Japan). Quinacrine dihydrochloride was purchased from EMD Biosciences (Darmstadt, Germany). {alpha}-Fluoromethylhistidine (FMH) was kindly provided by Prof. Zhong Cheng.

Data analysis. Values are expressed as means ± SD and one-way ANOVA analysis followed by Student-Newman-Keuls t-test was performed. A value of P < 0.05 was considered statistically significant.


   RESULTS
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 GRANTS
 REFERENCES
 
Colocalization of HA and NE in the superior cervical ganglia, axons, and varicosities. HA staining was localized to the somas of principal neurons within the SCG of guinea pig (Fig. 1). HA and NE were identified within the same neurons. The immunoreactivities of both HA and NE were significantly attenuated after chemical sympathectomy by 6-OHDA administration (Fig. 1). In the cardiac ventricle, the distribution of BDA anterogradely traced sympathetic axons and varicosities from SCG were observed. HA and NE were identified within the same traced axons or varicosities (Fig. 1). The numbers of neuron somas and varicosities exhibiting immunoreactivities for both HA and NE appeared to be 53% (35 of 66) and 51% (42 of 83), respectively.


Figure 1
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  		Fig. 1. Schematic diagram of a sympathetic neuron and images of laser scanning confocal microscopy showing immunostainings for norepinephrine (NE) and histamine (HA) in soma, axon, and varicosities of guinea pig superior cervical ganglion. A: HA and NE labeling were localized in the neuronal somas, and cellular coexistence of NE and HA was observed. Immunoreactivities of both NE and HA were significantly attenuated after chemical sympathetic nerve axotomy with 6-OHDA; B: colocalization of HA and NE in biotinylated dextran amine (BDA)-labeled cardiac sympathetic nerve axon; C: coexistence of HA and NE in cardiac sympathetic varicosities, combining BDA pathway traced anterogradely from the superior cervical ganglion (SCG). Scale bars = 50 or 10 µm, respectively.

 
Characterizations of HA exocytosis from cardiac synaptosomes. Depolarization of guinea pig cardiac sympathetic nerve endings (synaptosomes) with 50 mM K+ caused a release of endogenous HA and NE. The efflux of both HA and NE from cardiac synaptosomes was significantly reduced by pretreatment with 6-OHDA or reserpine (Fig. 2). Compound 48/80 (5 µg/ml), a mast cell HA releaser, did not increase background release of HA or K+-evoked HA release (Fig. 3A). Preincubation with the N-type Ca2+-channel blocker {omega}-CTX (100 nM) abolished K+-induced HA release, whereas the L-type Ca2+-channel blocker lacidipine (100 nM) did not affect HA release (Fig. 3B) (24, 35).


Figure 2
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  		Fig. 2. NE and HA release from cardiac sympathetic nerve endings (synaptosomes) by depolarization with 50 mM K+ and their inhibitions by pretreatment with 6-hydroxydopamine (6-OHDA) or reserpine. Effects of pretreatment with 6-OHDA (A) and with a vesicular monoamine transporte (VMAT2) inhibitor reserpine (B) are shown. Each bar represents concentration of released NE or HA (mean ± SD); n = 6 guinea pigs. ***P < 0.01, compared with corresponding value in normal, control group.

 

Figure 3
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  		Fig. 3. Effects of compound 48/80, {omega}-conotoxin ({omega}-CTX), and lacidipine on cardiac synaptosome HA release evoked by 50 mM K+. A: compound 48/80, a mast cell degranulator, caused neither significant release of HA nor potentiated K+-evoked HA release. ***P < 0.01, #P > 0.05, compared with the basal value of nontreatment, control group, +P > 0.05 vs. K+. B: {omega}-CTX (100 nM), a N-type Ca2+-channel antagonist, attenuated HA release, and lacidipine (100 nM), an L-type Ca2+-channel blocker, showed no effect on HA release. **P < 0.05 compared with basal value of nontreatment, control group, §§P < 0.05, +P > 0.05 vs. K+. Bars represent concentrations of released HA (mean ± SD), n = 6 guinea pigs.

 
Effects of L-histidine, FMH, and quinacrine on HA exocytosis. K+-evoked endogenous HA release was augmented by preloading the synaptosomes with L-histidine (100 nM); this increased release was inhibited by pretreatment with the histidine decarboxylase inhibitor FMH (0.1 µM) (Fig. 4A). After preincubation with the HA N-methyltransferase (HMT) inhibitor quinacrine (2 µM), the K+-induced HA release from cardiac synaptosomes increased from 3.46 ± 0.21 to 3.98 ± 0.16 pM (8). Quinacrine pretreatment further increased HA exocytosis from histidine-preloaded cardiac synaptosomes to 4.58 ± 0.34 pM (Fig. 4B) (39).


Figure 4
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  		Fig. 4. Effects of histidine, {alpha}-fluoromethyltransferase (FMH), and quinacrine on HA release from cardiac synaptosomes evoked by 50 mM K+. A: preloading with HA precursor histidine potentiated K+-evoked HA release, which was abolished by pretreatment with histidine decarboxylase inhibitor FMH (0.1 µM). **P < 0.05, compared with basal value of nontreatment, control group, ##P < 0.05 vs. K+, +++P < 0.01 vs. histidine + K+. B: preincubation of histamine N-methyltransferase (HNMT) inhibitor quinacrine (2 µM) with synaptosomes caused increase of K+-induced HA release. Preloading of histidine plus quinacrine showed synergic action on K+-evoked endogenous HA release from cardiac synaptosomes. **P < 0.05, compared with basal value of the nontreatment, control group, ##P < 0.05 vs. K+, +++P < 0.01 vs. quinacrine + K+. Bars represent concentrations of released HA (mean ± SD), n = 6 guinea pigs.

 
H3 receptor activation inhibited HA exocytosis. The H3 receptor agonist (R)-{alpha}-methylhistamine (MeHA, 0.3 µM) attenuated K+-evoked HA release from 3.75 ± 0.57 to 2.73 ± 0.68 pM. The inhibitory effect of MeHA was antagonized by the histamine H3 receptor antagonist thioperamide (0.3 µM) (Fig. 5A). Pretreatment with thioperamide alone increased K+-evoked release of endogenous HA from 2.83 ± 0.08 to 3.21 ± 0.17 pM. The potentiation action of thioperamide on HA release from cardiac synaptosomes was attenuated by {omega}-CTX treatment (Fig. 5B) but not affected by lacidipine (data not shown).


Figure 5
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  		Fig. 5. Effects of (R)-{alpha}-methylhistamine (MeHA) and thioperamide (Thio) on HA release from cardiac synaptosomes of guinea pig evoked by 50 mM K+. A: histamine H3 receptor agonist MeHA (0.3 µM) attenuated K+-evoked HA release, and H3 receptor antagonist Thio (0.3 µmol/l) antagonized effects of MeHA. ***P < 0.01, compared with basal value of nontreatment, control group, ##P < 0.05 vs. K+, +++P < 0.01 vs. MeHA + K+, n = 6. B: Thio pretreatment alone increased K+-evoked release of HA, and {omega}-CTX (100 nmol/l) prevented effects of Thio. **P < 0.05, compared with basal value of the nontreatment, control group, ##P < 0.05 vs. K+, ++P < 0.05 vs. Thio + K+, n = 6 guinea pigs. Bars represent concentrations of released HA (mean ± SD).

 
Endogenous HA modulated NE release from cardiac synaptosomes. As shown in Fig. 6, release of endogenous NE from guinea pig cardiac synaptosomes by depolarization with 50 mM K+ was detected. The preloading synaptosomes with L-histidine (1 µM) attenuated the K+-evoked endogenous NE release; this inhibitory effect was antagonized by pretreatment with FMH. When the synaptosomal preparation was preincubated with thioperamide, the histidine-mediated inhibition of NE exocytosis was completely reversed (Fig. 6A). The HMT inhibitor quinacrine also reduced K+-evoked exocytosis of NE from cardiac synaptosomes. The quinacrine-mediated inhibition of NE release was completely reversed in the presence of thioperamide (Fig. 6B).


Figure 6
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  		Fig. 6. Effects of endogenous HA on K+-evoked exocytosis of endogenous NE from cardiac synaptosomes. A: histindine preloading of synaptosomes inhibited NE release, which was prevented by pretreatment of FMH (0.1 µM) or antagonized by Thio (0.3 µM). **P < 0.05, compared with basal value of nontreatment, control group, ##P < 0.05 vs. K+, ++P < 0.05, §§P < 0.05 vs. histidine + K+. B: pretreatment of histamine N-methyltransferase (HNMT) inhibitor quinacrine (2 µM) with synaptosome reduced K+-evoked exocytosis of NE, which was completely reversed by Thio (0.3 µM). **P < 0.05, compared with basal value of nontreatment, control group, ##P < 0.05 vs. K+, ++P < 0.05 vs. quinacrine + K+, n = 6 guinea pigs. Bars represent concentrations of released NE (mean ± SD).

 

   DISCUSSION
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
GRANTS
 REFERENCES
 
Our previously published morphological studies revealed that HDC (a histamine-synthesizing enzyme) mRNA was detected in guinea pig SCG neurons, HA, and DbetaH colocalized in sympathetic neurons (20). The present results further demonstrate that HA coexists with NE within neuron somas of guinea pig SCG, and chemical sympathectomy can significantly attenuate the immunoreactivities of both HA and NE. Colocalization of HA and NE is also identified in the cardiac sympathetic axons and varicosities projected from SCG. Furthermore, functional evidence shows that release of HA from cardiac sympathetic nerve endings is greatly attenuated by 6-OHDA or reserpine pretreatment. Compound 48/80 has no effects on HA exocytosis. These findings indicate that the HA released from cardiac synaptosomes originates from a sympathetic neuronal source and that VMAT2, which is highly specific for HA, may be involved in HA transport into sympathetic nerve endings vesicles (18).

The exocytosis of neurotransmitters from postganglionic sympathetic neurons requires Ca2+ entry through voltage-dependent N-type Ca2+ channels (2, 4, 6). Interestingly, we have observed that the selective N-type Ca2+ channel antagonist {omega}-CTX, not the L-type Ca2+ channel blocker lacidipine, greatly inhibited K+-evoked HA release from cardiac synaptosomes. These findings reveal a similarity to the release of the sympathetic neurotransmitter NE from synaptosomes, which is inhibited by impeding Ca2+ influx into sympathetic nerve ending with {omega}-CTX (35), and indicate that release of HA from cardiac sympathetic nerve ending is exocytotic.

We found that preincubation with the HA precursor or inhibition of HMT activity increased the HA release from sympathetic nerve terminals. However, inhibition of HDC activity diminished the potentiation of HA release from preloaded histidine synaptosomes. This suggests that peripheral sympathetic HA, which shares properties with the HA in histaminergic neurons of the mammalian brain (17, 41), was synthesized from L-histidine by HDC and inactivated by HMT metabolism.

H3 receptors on cardiac adrenergic nerve endings have been identified as inhibitory heteroreceptors, which regulate the NE release (6, 12). Our data demonstrated that selective activation of presynaptic H3 receptors also inhibited HA release from the cardiac sympathetic terminals. H3 receptor antagonism attenuated this inhibitory effect and potentiated K+-evoked histamine release. All these findings indicate that the presynaptic H3 receptor is involved in modulating HA release from sympathetic terminals. Therefore, H3 receptors appear to be acting as inhibitory autoreceptors or homoreceptors.

We also investigated the importance of sympathetic HA in the regulation of NE release. Preloading histidine, or the presence of the HMT inhibitor, reduced the K+-evoked exocytosis of NE from cardiac synaptosomes. Whereas the HDC inhibitor antagonized histidine-induced reduction of NE exocytosis, H3-receptor antagonism completely reversed histidine- and quinacrine-induced inhibition of NE exocytosis. These data suggest that sympathetic endogenous HA is involved in the modulation of NE exocytosis from adrenergic nerve endings through activation of presynaptic histamine H3 receptors.

The finding of coexistence and corelease of HA and NE from sympathetic nerves in our experiments strongly suggests that HA, as a cotransmitter, may activate presynaptic HA H3 receptors to inhibit both HA and NE release from sympathetic terminals and act on postsynaptic myocardial H2 receptors to induce positive chronotropic and inotropic actions (Fig. 7).


Figure 7
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  		Fig. 7. Scheme of proposed mechanisms explaining negative feedback modulation of sympathetic neurotransmission through HA and H3 receptors. HA released from sympathetic terminals may activate sympathetic presynaptic H3 receptors, leading to inhibition of HA and NE release from sympathetic nerve endings.

 
Several studies have revealed that cardiac ganglia neurons contain enzymes involved in the synthesis of monoamines and HA, as well as immunoreactivities of dopamine, NE, serotonin, and HA (25, 36). Classically, cardiac ganglia are considered to be collections of cholinergic neurons that are distributed most densely at the atrial surface and absent in the ventricular myocardium (35, 37). In the present study, we used the ventricular parts of the guinea pig heart and found that HA and NE release was decreased from the guinea pig cardiac synaptosomes after 6-OHDA chemical sympathectomy. This suggests that the HA released from cardiac synaptosomes came from the cardiac sympathetic nerve endings.

Previously, six criteria have been used to confirm whether a molecule acts as a neurotransmitter at a given chemical synapse (5). First, the chemical must exist in the presynaptic neuron. Second, the enzymes for the synthesis of the transmitter must exist in the presynaptic terminals. Third, the substance must be released in response to presynaptic depolarization in a Ca2+-dependent manner. Fourth, specific receptors must be present on the postsynaptic membrane for the released transmitter. Fifth, experimental application of appropriate amounts of the chemical at the synapse should produce changes in postsynaptic potentials. Finally, blocking release of the substance should prevent presynaptic nerve impulses from altering the activity of the postsynaptic cell. Accordingly, based on the evidence obtained from previous and present studies, cardiac sympathetic HA comes close to satisfying these criteria (12, 16, 20, 23, 44). Therefore, sympathetic histamine may be a newly discovered sympathetic neurotransmitter.

In summary, the central findings of the present study are that HA coexists with NE within the sympathetic neuron and is coreleased with NE from cardiac sympathetic terminals. Additionally, sympathetic HA may modulate NE and its own release from cardiac sympathetic nerves via activation of presynaptic inhibitory H3 receptors. Further study is needed to elucidate the mechanism of this process and the physiological and pathophysiological roles of sympathetic HA in the modulation of sympathetic neurotransmission.


   GRANTS
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
REFERENCES
 
This work was supported by grants from the National Natural Science Foundation of China (NO. 39900075 and NO. 30300104) and PhD Project Foundation of The Fourth Military Medical University.


   ACKNOWLEDGMENTS
 
We thank Dr. Chen Tao, Chen Dan, and Prof. Zhang Jingshan for excellent technical assistance.


   FOOTNOTES
 

Address for reprint requests and other correspondence: X. Luo, Dept. of Pharmacology, The Fourth Military Medical Univ., Xian 710032, PR China (e-mail: xxluo3{at}fmmu.edu.cn)

The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.


   REFERENCES
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 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 

  1. Aloyo VJ, McIlvain HB, Bhavsar VH, and Roberts J. Characterization of norepinephrine accumulation by a crude synaptosomal-mitochondrial fraction isolated from rat heart. Life Sci 48: 1317–1324, 1991.[CrossRef][ISI][Medline]
  2. Boehm S and Huck S. Inhibition of N-type calcium channels: the only mechanism by which presynaptic alpha 2-autoreceptors control sympathetic transmitter release. Eur J Neurosci 8: 1924–1931, 1996.[CrossRef][ISI][Medline]
  3. Boehm S and Kubista H. Fine tuning of sympathetic transmitter release via ionotropic and metabotropic presynaptic receptors. Pharmacol Rev 54: 43–99, 2002.[Abstract/Free Full Text]
  4. Corrado Blandizzi C, Tognetti M, Colucci R, and Tacca MD. Histamine H3 receptors mediate inhibition of noradrenaline release from intestinal sympathetic nerves. Br J Pharmacol 129: 1387–1396, 2000.[CrossRef][ISI][Medline]
  5. Cowan WM and Kandel ER. A brief history of synapses and synaptic transmission. In: Synapses, edited by Südhof TC and Stevens CF. The Johns Hopkins University Press, 2001, p. 57.
  6. Endou M, Poli E, and Levi R. Histamine H3-receptor signaling in the heart: possible involvement of Gi/Go proteins and N-type Ca2+ channels. J Pharmacol Exp Ther 269: 221–229, 1994.[Abstract/Free Full Text]
  7. Fanger BO. Adaptation of the Bradford protein assay to membrane-bound proteins by solubilizing in glucopyranoside detergents. Anal Biochem 162: 11–17, 1987.[CrossRef][ISI][Medline]
  8. Grassmann S, Apelt J, Sippl W, Ligneau X, Pertz HH, Zhao YH, Arrang JM, Ganellin CR, Schwartz JC, Schunack W, and Stark H. Imidazole derivatives as a novel class of hybrid compounds with inhibitory histamine N-methyltransferase potencies and histamine hH3 receptor affinities. Bioorg Med Chem 11: 2163–2174, 2003.[CrossRef][Medline]
  9. Gross SS, Guo ZG, Levi R, Bailey WH, and Chenouda AA. Release of histamine by sympathetic nerve stimulation in the guinea pig heart and modulation of adrenergic responses. A physiological role for cardiac histamine? Circ Res 54: 516–526, 1984.[Abstract/Free Full Text]
  10. Hakanson R and Sundler F. Histamine-producing cells in the stomach and their role in the regulation of acid secretion. Scand J Gastroenterol Suppl 180: 88–94, 1991.[Medline]
  11. Happola O, Soinila S, Paivarinta H, Panula P, and Eranko O. Histamine-immunoreactive cells in the superior cervical ganglion and in the coeliac-superior mesenteric ganglion complex of the rat. Histochemistry 82: 1–3, 1985.[CrossRef][ISI][Medline]
  12. Hattori Y. Cardiac histamine receptors: their pharmacological consequences and signal transduction pathways. Methods Find Exp Clin Pharmacol 21: 123–31, 1999.[CrossRef][ISI][Medline]
  13. Hegstrand LR and Simon JR. Histidine transport into rat brain synaptosomes. J Neurochem 45: 407–414, 1985.[CrossRef][ISI][Medline]
  14. Imamura M, Seyedi N, Lander HM, and Levi R. Functional identification of histamine H3-receptors in the human heart. Circ Res 77: 206–210, 1995.[Abstract/Free Full Text]
  15. Imamura M, Smith Neil CE, Garbarg M, and Levi R. Histamine H3-receptor-mediated inhibition of calcitonin gene-related peptide release from cardiac C fibers. Circ Res 78: 863–869, 1996.[Abstract/Free Full Text]
  16. Kang YH, Wei HM, Fisher H, and Merrill GF. Histamine-induced changes in coronary circulation and myocardial oxygen consumption: influences of histamine receptor antagonists. FASEB J 1: 483–489, 1987.[Abstract]
  17. Kitanaka J, Kitanaka N, Tsujimura T, Terada N, and Takemura M. Histamine N-methyltransferase regulates histamine-induced phosphoinositide hydrolysis in guinea pig cerebellum. Neurosci Lett 308: 5–8, 2001.[CrossRef][ISI][Medline]
  18. Koerner P, Hesslinger C, Schaefermeyer A, Prinz C, and Gratzl M. Evidence for histamine as a transmitter in rat carotid body sensor cells. J Neurochem 91: 493–500, 2004.[CrossRef][ISI][Medline]
  19. Levi R and Smith NC. Histamine H(3)-receptors a new frontier in myocardial ischemia. J Pharmacol Exp Ther 292: 825–830, 2000.[Abstract/Free Full Text]
  20. Li M, Luo X, Chen L, Zhang J, Hu J, and Lu B. Co-localization of histamine and dopamine-bhydroxylase in sympathetic ganglion and release of histamine from cardiac sympathetic terminals of guinea-pig. Auton Autacoid Pharmacol 23: 327–333, 2003.[CrossRef][Medline]
  21. Luo XX, Tan YH, and Sheng BH. Histamine H3-receptors inhibit sympathetic neurotransmission in guinea pig myocardium. Eur J Pharmacol 204: 311–314, 1991.[CrossRef][ISI][Medline]
  22. Malinowska B, Godlewski G, and Schlicker E. Histamine H3 receptors general characterization and their function in the cardiovascular system. J Physiol Pharmacol 49: 191–211, 1998.[ISI][Medline]
  23. Matsuda N, Jesmin S, Takahashi Y, Hatta E, Kobayashi M, Matsuyama K, Kawakami N, Sakuma I, Gando S, Fukui H, Hattori Y, and Levi R. Histamine H1 and H2 receptor gene and protein levels are differentially expressed in the hearts of rodents and humans. J Pharmacol Exp Ther 309: 786–795, 2004.[Abstract/Free Full Text]
  24. Meyer P, Lang MG, Flammer J, and Lüscher TF. Effects of calcium channel blockers on the response to endothelin-1, bradykinin and sodium nitroprusside in porcine ciliary arteries. Exp Eye Res 60: 505–510, 1995.[CrossRef][ISI][Medline]
  25. Moravec M, Moravec J, and Forsgren S. Catecholaminergic and peptidergic nerve components of intramural ganglia in the rat heart: an immunohistochemical study. Cell Tissue Res 262: 315–327, 1990.[CrossRef][ISI][Medline]
  26. Nemmar A, Delaunois A, Beckers JF, Sulon J, Bloden S, and Gustin P. Modulatory effect of imetit, a histamine H3 receptor agonist, on C-fibers, cholinergic fibers and mast cells in rabbit lungs in vitro. Eur J Pharmacol 371: 23–30, 1999.[CrossRef][ISI][Medline]
  27. Paivarinta H, Happola O, Joh TH, Steinbusch H, Watanabe T, and Panulta P. Immunocytochemical colocalization of histamine, histidine decarboxylase, 5-hydroxytryptamine and tyrosine hydroxylase in the superior cervical ganglion of the rat. Histochem J 19: 319–326, 1987.[CrossRef][ISI][Medline]
  28. Panula P, Kaartinen M, Macklin M, and Costa E. Histamine-containing peripheral neuronal and endocrine systems. J Histochem Cytochem 33: 933–941, 1985.[Abstract]
  29. Reiner A, Veenman CL, Medina L, Jiao Y, Del Mar N, and Honig MG. Pathway tracing using biotinylated dextran amines. J Neurosci Methods 103: 23–37, 2000.[CrossRef][ISI][Medline]
  30. Rodriguez-Sosa L, Picones A, Rosete G, and Arechigay S. Localization and release of 5-hydroxytryptamine in the crayfish eyestalk. J Exp Biol 200: 3067–3077, 1997.[Abstract]
  31. Schlicker E, Malinowska B, Kathmann M, and Gothert M. Modulation of neurotransmitter release via histamine H3 heteroreceptors. Fundam Clin Pharmacol 8: 128–137, 1994.[ISI][Medline]
  32. Schneider E, Rolli-Derkinderen M, Arock M, and Dy M. Trends in histamine research: new functions during immune responses and hematopoiesis. Trends Immunol 23: 255–263, 2002.[CrossRef][ISI][Medline]
  33. Seyedi N, Koyama M, Mackins CJ, and Levi R. Ischemia promotes renin activation and angiotensin formation in sympathetic nerve terminals isolated from the human heart: contribution to carrier-mediated norepinephrine release. J Pharmacol Exp Ther 302: 539–544, 2002.[Abstract/Free Full Text]
  34. Shore PA, Burkhalter A, and Cohn VH Jr. A method for the fluorometric assay of histamine in tissues. J Pharmacol Exp Ther 127: 182–186, 1959.[Abstract/Free Full Text]
  35. Silver RB, Poonwasi KS, Seyedi N, Wilson SJ, Lovenberg TW, and Levi R. Decreased intracellular calcium mediates the histamine H3-receptor-induced attenuation of norepinephrine exocytosis from cardiac sympathetic nerve endings. Proc Natl Acad Sci USA 99: 501–506, 2002.[Abstract/Free Full Text]
  36. Singh S, Johnson PI, Javed A, Gray TS, Lonchyna VA, and Wurster RD. Monoamine- and histamine-synthesizing enzymes and neurotransmitters within neurons of adult human cardiac ganglia. Circulation 99: 411–419, 1999.[Abstract/Free Full Text]
  37. Singh S, Johnson PI, Lee RE, Orfei E, Lonchyna VA, Sullivan HJ, Montoya A, Tran H, Wehrmacher WH, and Wurster RD. Topography of cardiac ganglia in the adult human heart. J Thorac Cardiovasc Surg 112: 943–953, 1996.[Abstract/Free Full Text]
  38. Starke K. Presynaptic {alpha}-autoreceptors. Rev Physiol Biochm Pharmacol 107: 73–146, 1987.
  39. Szeberenyi JB, Pallinger E, Zsinko M, Pos Z, Rothe G, Orso E, Szeberenyi S, Schmitz G, Falus A, and Laszlo V. Inhibition of effects of endogenously synthesized histamine disturbs in vitro human dendritic cell differentiation. Immunol Lett 76: 175–182, 2001.[CrossRef][ISI][Medline]
  40. Vinkenoog M, van den Oever MC, Uylings HB, and Wouterlood FG. Random or selective neuroanatomical connectivity. Study of the distribution of fibers over two populations of identified interneurons in cerebral cortex. Brain Res Protocol 14: 67–76, 2005.[CrossRef][Medline]
  41. Wada H, Inagaki N, Itowi N, and Yamatodani A. Histaminergic neuron system in the brain: distribution and possible functions. Brain Res Bull 27: 367–370, 1991.[CrossRef][ISI][Medline]
  42. Weil-Malherbe H and Bigelow LB. The fluorometric estimation of epinephrine and norepinephrine: an improved modification of the trihydroxyindole method. Anal Biochem 22: 321–334, 1968.[CrossRef][ISI][Medline]
  43. Weinreich D. Multiple sites of histamine storage in superior cervical ganglia. Exp Neurol 90: 36–43, 1985.[CrossRef][ISI][Medline]
  44. Wolff AA and Levi R. Histamine and cardiac arrhythmias. Circ Res 58: 1–16, 1986.[Free Full Text]



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H. L. Haas, O. A. Sergeeva, and O. Selbach
Histamine in the Nervous System
Physiol Rev, July 1, 2008; 88(3): 1183 - 1241.
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