| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Thoracic and Cardiovascular Surgery and 2 Department of Internal Medicine, Kansai Medical University, Moriguchi, Osaka 570-8507, Japan
 |
ABSTRACT |
|---|
 TOP
 ABSTRACT
 INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Although Na+/H+ exchange (NHE) has been implicated in myocardial reperfusion injury, participation of coronary microvascular endothelial cells (CMECs) in this pathogenesis has been poorly understood. NHE-induced intracellular Ca2+ concentration ([Ca2+]i) overload in CMECs may increase the synthesis of intercellular adhesion molecules (ICAM), which is potentially involved in myocardial reperfusion injury. The present study tested the hypothesis that NHE plays a crucial role in [Ca2+]i overload and ICAM-1 synthesis in CMECs. Primary cultures of CMECs isolated from adult rat hearts were subjected to acidic hypoxia for 30 min followed by reoxygenation. Two structurally distinct NHE inhibitors, cariporide and 5-(N-N-dimethyl)-amiloride (DMA), had no significant effect on the acidic hypoxia-induced decrease in intracellular pH (pHi) of CMECs but significantly retarded pHi recovery after reoxygenation. These NHE inhibitors abolished the hypoxia- and reoxygenation-induced increase in [Ca2+]i. Expression of ICAM-1 mRNA was markedly increased in the vehicle-treated CMECs 3 h after reoxygenation, and this was significantly inhibited by treatment with cariporide, DMA, or Ca2+-free buffer. In addition, enhanced ICAM-I protein expression on the cell surface of CMECs 8 h after reoxygenation was attenuated by treatment with cariporide, DMA, or Ca2+-free buffer. These results suggest that NHE plays a crucial role in the rise of [Ca2+]i and ICAM-1 expression during acidic hypoxia/reoxygenation in CMECs. We propose that inhibition of ICAM-1 expression in CMECs may represent a novel mechanism of action of NHE inhibitors against ischemia-reperfusion injury.
myocardial ischemia-reperfusion; intracellular pH; intracellular Ca2+; intercellular adhesion molecule-1
| |
INTRODUCTION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
THE ROLE OF THE CORONARY MICROCIRCULATION in myocardial reperfusion injury has gained increasing attention in recent years. Enhanced expression of intercellular adhesion molecules (ICAM) in coronary microvascular endothelial cells (CMECs) has been demonstrated to play a crucial role in myocardial reperfusion injury in vivo (13). Neutrophil interaction with CMECs through ICAM provokes mechanical obstruction of small vessels and chemical assault to adjacent cells, including cardiomyocytes (6, 8). The importance of ICAM in the development of myocardial reperfusion injury has prompted us to investigate the mechanism for ICAM expression in CMECs under the condition of simulated ischemia in vitro.
The release of adhesion molecules from CMECs at the time of reperfusion is presumed to occur as a response to injurious stress incurred by ischemia and reperfusion. Although various events are implicated in this stress, intracellular Ca2+ concentration ([Ca2+]i) overload has been thought to be the major pathogenesis of ischemia-reperfusion injury (24). In cardiomyocytes, [Ca2+]i overload during ischemia and reperfusion is provoked predominantly through an Na+/H+ exchange (NHE)-dependent mechanism, which is activated during recovery from intracellular acidosis (17, 25). Recent experimental studies (9, 10, 20) have indeed demonstrated the benefit of employing NHE inhibitors in alleviating postischemic myocardial injury. However, those in vivo studies did not discriminate the beneficial effects of NHE inhibitors on cardiomyocytes from those on endothelial cells. It is anticipated that endothelial cells may also be involved in myocardial reperfusion injury by enhanced expression of ICAM through NHE-induced [Ca2+]i overload. In the present study, we tested the hypothesis that NHE-induced [Ca2+]i overload plays an essential role in ICAM-1 expression in cultured CMECs subjected to simulated ischemia and reperfusion.
| |
METHODS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Cell culture. An axenic culture of rat CMECs were prepared according to Nishida et al. (22). Briefly, hearts obtained from male Sprague-Dawley rats (250-300 g) were perfused for 5 min in a Langendorff apparatus with Krebs-Henseleit bicarbonate (KHB) buffer consisting of (in mmol/l) 118 NaCl, 4.7 KCl, 2.55 CaCl2, 1.18 MgSO4, 1.18 KH2PO4, 24.8 NaHCO3, and 11.1 glucose, saturated with a 95% O2-5% CO2 gas mixture at pH 7.4. The left ventricular myocardial tissue was then quickly removed and immersed in 70% ethanol for 30 s to devitalize endocardial endothelial cells. The outer one-fourth of the left ventricular free wall was dissected away to remove epicardial large vessels, and the remaining heart tissue was minced finely and incubated in Ca2+-free KHB buffer containing 0.2% collagenase and 0.02% trypsin for 30 min at 37°C. The cells obtained were filtered through a 100-µm mesh filter and washed with Ca2+-free KHB buffer, followed by centrifugation at 100 g for 1 min twice. The cells were resuspended in DMEM supplemented with 20% fetal calf serum and antibiotics (100 IU/ml penicillin and 100 µg/ml streptomycin) and plated on glass-bottom dishes (Matsunani Glass; Osaka, Japan).
Validation of the axenic culture. A fluorescent reagent specific to endothelial cells, acetylated low-density lipoprotein (LDL) labeled with 1,1'-dioctadecyl-1,3,3,3',3'-tetramethyl-indocarbocyanine (DiI-Ac-LDL) (Paesel and Lorei; Duisburg, Germany), was added to the cultured cells at 10 µg/ml and incubated overnight at 37°C. The dye uptake was viewed with a confocal laser microscope at an emission wavelength of 590 nm with an excitation at 568 nm (Fluo View, Olympus; Tokyo, Japan). In the same manner, 10 µg/ml DiI-Ac-LDL was added to the cultured cells and incubated overnight at 37°C. The DiI-Ac-LDL-loaded cells were analyzed with a fluorescence-activated cell sorter (FACS; Becton-Dickinson; San Jose, CA).
Measurements of intracellular pH. The intracellular pH (pHi) and [Ca2+]i under conditions of both acidic hypoxia and reoxygenation were measured in the absence (0.1% DMSO only added as a vehicle) or the presence of two structurally distinct NHE inhibitors, 5-(N-N-dimethyl)-amiloride (DMA; Sigma) and 4-isopropyl-3-methylsulphonyl-guanidine methanesulphonate (HOE-642, cariporide; gift of Hoechst AG; Frankfurt, Germany). Low concentrations of DMA (30 µmol/l) and cariporide (3 µmol/l) were employed to elicit a specific effect on NHE, whereas high concentrations of DMA (100 µmol/l) and cariporide (10 µmol/l) are known to exert a nearly maximum effect on NHE. pHi and [Ca2+]i were measured according to previous reports (3, 23). Cultured CMECs in a glass-bottom dish with a cover glass were placed on an inverted fluorescence microscope (BH2-QRFL, Olympus) equipped with a ×40 immersion fluorescence lens at 37°C, and the microscope was focused on single cells. pHi measurements were performed on cells loaded with a pH-sensitive fluorescent dye, 5 µmol/l 2',7'-bis-(2-carboxyethyl)-5-(and -6)-carboxyfluorescein-AM (Wako Pure Chemical; Osaka, Japan), which were treated for 20 min at 37°C in serum-free culture medium. The medium was then replaced with KHB buffer (pH 7.4) equilibrated with a gas mixture of 5% CO2-95% air. With the use of a super-voltage xenon lamp as a light source, the fluorescence at an emission wavelength of 540 nm was measured with excitation at two wavelengths, 490 and 450 nm, and the control value of the fluorescence ratio was obtained. When the fluorescence ratio became stable, the solution was replaced by glucose-free KHB buffer adjusted at pH 6.8 with 5 N HCl. The hypoxic condition was maintained by equilibrating with a gas mixture of 5%CO2-95% N2 at 37°C. After 30 min under the hypoxic condition, reoxygenation was introduced with normal KHB buffer.
After each experiment was completed, 10 µmol/l nigericin (Sigma), a H+ ionophore, was added to the pH calibration buffers [consisting of (in mmol/l) 10 HEPES, 120 KCl, and 25 NaCl] at pH 6.6, 6.8, 7.0, 7.2, and 7.4 and adjusted with 1 mol/l KOH, and the fluorescence intensity of each single cells was assayed according to a calibration curve for pHi.Measurements of [Ca2+]i. In the experiments with cariporide, [Ca2+]i measurements were performed by loading the cells with 5 µmol/l fura 2-AM (Wako Pure Chemical), a Ca2+-sensitive fluorescent dye, for 30 min at 37°C. The fluorescence at an emission wavelength of 510 nm was measured with excitation at two wavelengths, 340 and 380 nm, and the fluorescence ratio was determined at 5-min intervals under the same conditions as employed for pHi measurements. After each experiment was completed, 5 µmol/l ionomycin (Sigma) was added to the Ca2+ calibration buffer [consisting of (in mmol/l) 10 HEPES, 130 KCl, 120 NaCl, 2 EGTA, and 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, or 1.8 CaCl2] at pH 7.05, adjusted with 1 mol/l KOH. Calibration curves were prepared for each treatment condition, and the Ca2+ concentrations were obtained from the fluorescence intensity ratio. The concentration of Ca2+ was calculated from the dissociation constants of Ca2+ and EGTA as 214 nmol/l (37°C at pH 7.05) (7).
Because DMA possesses autofluorescence at a wavelength of 340 nm, [Ca2+]i measurements in DMA-treated CMECs were performed by loading cells with 5 µmol/l fluo 3- AM (Wako Pure Chemical), a Ca2+-sensitive fluorescent, for 30 min at 37°C. Fluorescence was measured according to previous reports (12, 23) every 5 min under the same conditions as employed for pHi measurements at an emission wavelength of 530 nm with excitation at one wavelength, 490 nm. As in the [Ca2+]i measurements with fura 2-AM, Ca2+ calibration buffer and 5 µmol/l ionomycin (Sigma) were employed, and a calibration curve was prepared for the determination of Ca2+ concentrations.Northern blot analysis for ICAM-1 mRNA. The level of ICAM-1 mRNA expressed in endothelial cells was determined by a Northern blotting assay using guanidinium isothiocyanate-cesium chloride centrifugation, fractionated on 1% agarose-formaldehyde gels, and transferred to nylon membranes as previously reported (21). Blots were then hybridized with random-primed 32P-labeled cDNA probes consisting of ICAM-1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal control. Hybridized signals were measured by scanning densitometry, and ICAM-1 mRNA levels were arbitrarily normalized relative to the GAPDH mRNA levels. A 1,600-bp ICAM-1 cDNA was the gift of Dr. T. Horiuchi (Daiichi Pharmaceuticals, Tokyo, Japan).
CMECs were incubated overnight in serum-free DMEM and subjected to acidic hypoxia and reoxygenation in the absence or the presence of cariporide or DMA as employed in pHi and [Ca2+]i measurements. Nominally Ca2+-free KHB buffer was also utilized during acidic hypoxia and reoxygenation to clarify the role of Ca2+ in ICAM-1 expression. ICAM-1 mRNA levels were measured at 30 min and 1 and 3 h after reoxygenation.Immunostaining for ICAM-1 protein. CMECs were incubated overnight in serum-free DMEM medium and subjected to acidic hypoxia and reoxygenation in the absence or the presence of cariporide or DMA as employed in pHi and [Ca2+]i measurements. CMECs were also incubated in nominally Ca2+-free KHB buffer during acidic hypoxia and reoxygenation. CMECs obtained before exposure to acidic hypoxia and at 4 and 8 h after reoxygenation were fixed with 4% paraformaldehyde for 45 min at 4°C. The slides were first treated with anti-rat ICAM-1 mouse monoclonal antibody (R&D Systems; Oxford, UK) and then incubated with fluorescein isothiocyanate-conjugated anti-mouse rabbit immunoglobulin (Dako Japan; Tokyo, Japan) as a secondary antibody. The fluorescence was viewed with a confocal laser microscope (Fluo View, Olympus) at an emission wavelength of 535 nm with excitation at 488 nm.
All experiments were conducted in accordance with the Guidelines for the Care and Use of Laboratory Animals (NIH publication No. 86-23, Revised 1985).Statistics. All data are expressed as means ± SE. Statistical analysis was performed with one-way ANOVA followed by pairwise contrasts (vehicle vs. treatments) using Dunnett's comparison test. Values of P < 0.05 were considered significant.
| |
RESULTS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
DiI-Ac-LDL uptake by cultured CMECs.
Microvascular endothelial cells are known to incorporate DiI-Ac-LDL
specifically in their cytosol (22). All the cultured cells
were found to incorporate DiI-Ac-LDL by observation with a confocal
laser microscope, although the degree of uptake and the staining
pattern were heterogeneous (Fig.
1A). The purity of primary
isolates of CMECs was confirmed by FACS. In contrast to unloaded cells,
there was a distinct rightward shift in the peak fluorescence intensity
(Fig. 2B), revealing a
relatively homogeneous pattern of the staining. Therefore, the low
level of heterogeneous cell contamination in primary isolates of rat CMECs allowed us to avoid routine cell sorting of DiI-Ac-LDL-positive cells. However, FACS analysis of DiI-Ac-LDL-loaded rat CMECs was employed routinely as a means of validating the efficiency of the CMEC
isolation technique.
|
|
Effects of cariporide and DMA on pHi during acidic hypoxia and reoxygenation in CMECs. Acidic hypoxia resulted in a rapid decrease of pHi in CMECs (Fig. 2). The rate and the magnitude of the decline of pHi during acidic hypoxia were not significantly different among CMECs treated with vehicle and low and high concentrations of NHE inhibitors. Upon reoxygenation, however, rapid recovery of pHi was noted only in the vehicle-treated CMECs, and pHi returned to the baseline level by 15 min after reoxygenation in these CMECs. In contrast, the recovery of pHi after reoxygenation was significantly retarded in CMECs treated with low and high concentrations of cariporide or DMA. However, the pHi of these CMECs returned to the baseline level by 30 min after reoxygenation.
Effects of cariporide and DMA on
[Ca2+]i
during acidic hypoxia and reoxygenation in CMECs.
In the fura 2-loaded CMECs, significant elevation of
[Ca2+]i was observed 15 min after acidic
hypoxia (Fig. 3A). There was
nearly fourfold increase in [Ca2+]i level at
the end of acidic hypoxia and during early reoxygenation. Treatment
with a low dose of cariporide significantly inhibited the rise in
[Ca2+]i during the late hypoxia and
reoxygenation, whereas a high dose of cariporide completely abrogated
the elevation of [Ca2+]i during these
periods. In the fluo 3-treated CMECs, a similar baseline value of
[Ca2+]i was obtained, and a significant
increase in [Ca2+]i was observed in the
vehicle-treated CMECs 20 min after acidic hypoxia (Fig.
4B). The time course and the
magnitude of [Ca2+]i elevation during acidic
hypoxia and reoxygenation in the vehicle-treated CMECs were comparable
with those observed in CMECs loaded with fura 2. Treatment with
a low dose of DMA significantly inhibited the rise in
[Ca2+]i during late hypoxia and
reoxygenation, whereas a high dose of DMA completely abrogated the
elevation of [Ca2+]i during these periods.
|
|
Effects of cariporide, DMA, and Ca2+-free buffer on expression of ICAM-1 mRNA in CMECs. There was no appreciable expression of ICAM mRNA 1 h after reoxygenation in the vehicle-treated CMECs (Fig. 4). However, ICAM-1 mRNA expression was markedly increased 3 h after reoxygenation in these CMECs. Treatment with a high dose of cariporide, DMA, or nominally Ca2+-free buffer during acidic hypoxia and reoxygenation markedly attenuated ICAM-1 mRNA expression 3 h after reoxygenation. Quantitative analysis showed that expression of ICAM-1 mRNA 3 h after reoxygenation was highly significantly inhibited in CMECs treated with cariporide, DMA, or Ca2+-free buffer. There were no significant differences in ICAM-1 mRNA expression among the cariporide, DMA, and Ca2+-free buffer groups.
Effects of cariporide, DMA, and
Ca2+-free buffer on
expression of ICAM-1 protein in CMECs.
Immunofluorescent confocal laser microscopy showed no appreciable
expression of ICAM-1 protein on CMECs before acidic hypoxia (Fig.
5A). However, ICAM-1 protein
expression was enhanced in vehicle-treated CMECs 4 h after
reoxygenation (Fig. 5B). The immunofluorescence staining was
predominantly localized on the cell surface, indicating the
localization of ICAM-I protein on the cell membrane. The
immunofluorescence staining was markedly increased 8 h after
reoxygenation (Fig. 5C). Treatment with a high dose of
cariporide, DMA, or Ca2+-free buffer during acidic hypoxia
and reoxygenation attenuated ICAM-1 protein expression on CMECs (Fig.
5, D-F). Similar results were observed in four other
separate experiments in each group.
|
| |
DISCUSSION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Rationale for employing CMECs. The mechanism for expression of adhesion molecules has been extensively investigated in cultured vascular endothelial cells (11, 16, 19). However, those studies employed endothelial cell types other than CMECs. It is known that the phenotypic differences in vascular endothelial cells markedly influence physiological responses and gene expression. For example, endothelial cells derived from the large vessels are positive for the von Willebrand factor, whereas those derived from the small vessels are lacking in granular immunoreactivity for this commonly used endothelial cell marker (22). Moreover, microvascular endothelial cells contribute directly to tissue injury by expressing adhesion molecules under certain pathological conditions. Inflammatory cell adherence with endothelial cells in the capillaries deteriorates the microcirculation by obstructing the vessel lumen, which hardly ever occurs in the large vessels. These inflammatory cells can also readily gain access to cardiomyocytes and attack them by releasing reactive oxygen species and cytokines. Accordingly, the role of endothelial cell synthesis of adhesion molecules in acute tissue injury is more crucial in the microcirculation than in large vessels. Therefore, we employed CMECs to investigate the possible involvement of a NHE mechanism, a major pathogenesis of myocardial reperfusion injury (10, 20, 24), in ICAM-1 expression. The results of the present study provide evidence, for the first time, that NHE plays a crucial role in [Ca2+]i overload and ICAM-1 expression during acidic hypoxia and reoxygenation in CMECs.
Role of NHE in pHi and [Ca2+]i regulations in CMECs. It was found that pHi in CMECs decreased with time starting immediately after exposure to acidic hypoxia irrespective of the absence or presence of NHE inhibitors without a significant intergroup difference. This result was unexpected, because the use of NHE inhibitors was thought to further decrease pHi during acidic hypoxia. Because the high concentration of DMA and cariporide employed in the present study is known to exert a nearly maximum effect on NHE activities in vitro, it is unlikely that these NHE inhibitors failed to block NHE activities in cultured CMECs. It is rather likely that these NHE inhibitors had no further effect under the acidic environment, because low extracellular pH inhibits NHE activity. Alternatively, when pHi decreases below extracellular pH, the NHE system could be activated and participated in pHi and [Ca2+]i regulation. Stimulation of NHE activity then provokes an intracellular Na+ concentration accumulation, which in turn activates reverse-mode Na+/Ca2+ exchange, leading to an influx of Ca2+ into the cells and [Ca2+]i overload. Indeed, [Ca2+]i was increased during late hypoxia, and NHE inhibitors prevented an increase in [Ca2+]i. This abrogation of [Ca2+]i overload by NHE inhibitors may be attributed to no amplification of intracellular acidosis compared with vehicle. It has been suggested that inhibition of [Ca2+]i overload by NHE inhibitors prevents stimulation of Ca2+-activated ATPases and subsequent H+ production coupled with ATP hydrolysis in the ischemic rabbit myocardium (10). A similar mechanism may be operative in our CMECs treated with NHE inhibitors during acidic hypoxia.
Upon reoxygenation at normal extracellular pH, pHi increased immediately and returned to the baseline level within 15 min after reoxygenation in the vehicle-treated CMECs, whereas recovery of pHi after reoxygenation was significantly retarded in CMECs treated with NHE inhibitors. The evidence that the retarded recovery of pHi was associated with inhibition of an increase in [Ca2+]i in CMECs is consistent with the hypothesis that the NHE mechanism plays a critical role in the recovery from intracellular acidosis at the time of reoxygenation and is responsible for the rise of [Ca2+]i during reoxygenation in CMECs. However, caution must be exerted in interpreting the results because the buffer contains HCO
Role of NHE in ICAM-1 expression. A marked increase in ICAM-1 mRNA and ICAM-1 protein expression after reoxygenation after acidic hypoxia in cultured CMECs was attenuated by treatment with cariporide, DMA, and Ca2+-free buffer. Because the NHE inhibitors abolished the increase in [Ca2+]i during hypoxia and reoxygenation and ICAM-1 expression was inhibited by the NHE inhibitors and Ca2+-free buffer, our results suggest that NHE-induced [Ca2+]i overload participates in the enhanced expression of ICAM-1 in CMECs. Because Ca2+ is the most common signal transduction element in cells (2, 4, 15), the increase in [Ca2+]i is responsible for activating intracellular signaling pathways, promoting ICAM-1 gene expression. This assumption is in contrast to the report of Kupatt et al. (14), who proposed that a nitric oxide-sensitive mechanism generating reactive oxygen species is responsible for enhanced ICAM-1 expression during reoxygenation in primary cultures of rat CMECs. A possible explanation for this difference in causative factors involved in ICAM-1 expression may be related to the difference in experimental models. In the experiments by Kupatt et al. (14), CMECs were made hypoxic for 20 h followed by reoxygenation without artificially changing the buffer pH, whereas in our experiments CMECs were placed in acidic hypoxia for 30 min followed by sudden normalization of the buffer pH and reoxygenation. Therefore, in the former model, oxidative stress associated with hypoxia/reoxygenation may be the most important factor involved in enhanced ICAM-1 expression, whereas in the latter model [Ca2+]i overload, mediated presumably through the NHE system, plays a more crucial role in enhanced ICAM-1 expression. Nevertheless, these two essential components of ischemia-reperfusion injury in vivo could stimulate a common intracellular signaling pathway that converges in ICAM-1 expresssion.
Clinical implication. There is a growing body of evidence in favor of the notion that neutrophil adhesion with endothelial cells in the small vessels plays a crucial role in the progression of myocardial injury after ischemia and reperfusion. It has been reported that myocardial infarct size after temporary regional ischemia is reduced by neutrophil depletion at the time of reperfusion (27) or by inhibition of adhesion of neutrophils with vascular endothelial cells (28). Rochitte et al. (26) recently reported that the area of "no-reflow" due to microvascular obstruction expands for up to 48 h during reperfusion after temporary regional ischemia, which is in accordance with an increase in infarct size. The role of neutrophil adhesion in exacerbating ischemia-reperfusion injury may not be confined to mechanical plugging of the small vessels but can also be attributed to chemical injury mediated by reactive oxygen species and cytokines released from neutrophils activated upon adhesion with CMECs. Neutrophil adhesion with endothelial cells is known to be promoted by a number of adhesion molecules, including ICAM-1, vascular cell adhesion molecules, and selectins. Although the present study examined the effect of NHE inhibitors on the expression of ICAM-1 only, it is likely that NHE inhibition is also effective in attenuating the expression of other endothelial cell adhesion molecules, because expression of those adhesion molecules shares a common intracellular signaling pathway with ICAM-1, i.e., transient [Ca2+]i overload (1). Treatment of the acutely ischemic heart with NHE inhibitors may inhibit neutrophil adhesion with CMECs and their activation by attenuating the expression of endothelial cell adhesion molecules. NHE inhibitors thus represent a promising tool in preventing neutrophil-mediated myocardial reperfusion injury. Such a potential benefit conferred by NHE inhibitors must be investigated further but should be considered as a novel mechanism of myocardial protection against reperfusion injury.
| |
ACKNOWLEDGEMENTS |
|---|
We thank Aya Kobayashi for excellent technical assistance.
| |
FOOTNOTES |
|---|
This work was supported in part by Scientific Research Grant 08671551 from the Ministry of Education, Science, and Culture of Japan.
Address for reprint requests and other correspondence: H. Otani, Dept. of Thoracic and Cardiovascular Surgery, Kansai Medical Univ., 10-15 Fumizono-cho, Moriguchi City, Osaka 570-8507, Japan (E-mail: otanih{at}takii.kmu.ac.jp).
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.
Received 30 May 2000; accepted in final form 24 January 2001.
| |
REFERENCES |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
1.
Allen, S,
Khan S,
Al-Mohanna F,
Batten P,
and
Yacoub M.
Native low density lipoprotein-induced calcium transients trigger VCAM-1 and E-selectin expression in cultured human vascular endothelial cells.
J Clin Invest
101:
1064-1075,
1998[Web of Science][Medline].
2.
Berridge, MJ.
Inositol trisphosphate and calcium signaling.
Nature
361:
315-325,
1993[Medline].
3.
Borzak, S,
Kelly RA,
Kramer BK,
Matoba Y,
Marsh JD,
and
Reers M.
In-situ calibration of fura 2 and BCECF fluorescence in adult rat ventricular myocytes.
Am J Physiol Heart Circ Physiol
259:
H973-H981,
1990
4.
Brinson, AE,
Harding T,
Diliberto PA,
He Y,
Li X,
Hunter D,
Herman B,
Earp HS,
and
Graves LM.
Regulation of a calcium-dependent tyrosine kinase in vascular smooth muscle cells by angiotensin II and platelet-derived growth factor.
J Biol Chem
273:
1711-1718,
1998
5.
Brown, L,
Cragoe EJ, Jr,
Abel KC,
Manley SW,
and
Bourke JR.
Amiloride analogues induce responses in isolated rat cardiovascular tissues by inhibition of Na+/Ca2+ exchange.
Arch Pharmacol
344:
220-224,
1991.
6.
Engler, R,
Schnid-Schonbein GW,
and
Pavelec RS.
Leukocyte capillary plugging in myocardial ischemia and reperfusion in the dog.
Am J Pathol
111:
98-111,
1983[Abstract].
7.
Fabiato, A,
and
Fabiato F.
Calculator programs for computing the composition of the solutions containing multiple metals and ligands used for experiments in skinned muscle cells.
J Physiol (Paris)
75:
463-505,
1979[Medline].
8.
Forman, MB,
Puett DW,
and
Virmani R.
Endothelial and myocardial injury during ischemia and reperfusion: pathogenesis and therapeutic implications.
J Am Coll Cardiol
13:
450-459,
1989[Abstract].
9.
Gumina, RJ,
Buerger E,
Euckmeier C,
Moore J,
Daemmgen J,
and
Gross GJ.
Inhibition of the Na+/H+ exchanger confers greater cardioprotection against 90 min of myocardial ischemia than ischemic preconditioning in dogs.
Circulation
100:
2519-2526,
1999
10.
Hendrikx, M,
Mubagwa K,
Verdonck F,
Overloop K,
Van Hecke P,
Vanstapel F,
Van Lommel A,
Verbeken E,
Lauweryns J,
and
Flameng W.
New Na+-H+ exchange inhibitor HOE 694 improves postischemic function and high-energy phosphate resynthesis and reduces Ca2+ overload in isolated perfused rabbit heart.
Circulation
89:
2787-2798,
1994
11.
Huang, ZH,
Bates EJ,
Ferrante JV,
Hii CST,
Poulos A,
Robinson BS,
and
Ferrante A.
Inhibition of stimulus-induced endothelial cell intercellular adhesion molecule-1, E-selectin, and vascular cellular adhesion molecule-1 expression by arachidonic acid and its hydroxy and hydroperoxy derivatives.
Circ Res
80:
149-158,
1997
12.
Ikeda, M,
Ariyoshi H,
Kambayashi J,
Fujitani K,
Shinoki N,
Sakon M,
Kawasaki T,
and
Monden M.
Separate analysis of nuclear and cytosolic Ca2+ concentrations in human umbilical vein endothelial cells.
J Cell Biol
63:
23-26,
1996.
13.
Kukielka, GL,
Hawkins HK,
Michael L,
Manning AM,
Youker K,
Lane C,
Entman ML,
Smith CW,
and
Anderson DC.
Regulation of intercellular adhesion molecule-1 (ICAM-1) in ischemic and reperfused canine myocardium.
J Clin Invest
92:
1504-1516,
1993.
14.
Kupatt, C,
Weber C,
Wolf DA,
Becker BF,
Smith TW,
and
Kelly RA.
Nitric oxide attenuates reoxygenation-induced ICAM-1 expression in coronary microvascular endothelium: role of NF
B.
J Mol Cell Cardiol
29:
2599-2609,
1997[Web of Science][Medline].
15.
Lane, TA,
Lamkin GE,
and
Wancewicz EV.
Modulation of endothelial cell expression of intercellular adhesion molecule 1 by protein kinase C activation.
Biochem Biophys Res Commun
161:
945-952,
1989[Web of Science][Medline].
16.
Lane, TA,
Lamkin GE,
and
Wancewicz EV.
Protein kinase C inhibitors block the enhanced expression of intercellular adhesion molecule-1 on endothelial cells activated by interleukin-1, lipopolysaccharide and tumor necrosis factor.
Biochem Biophys Res Commun
172:
1273-1281,
1990[Web of Science][Medline].
17.
Lazdunski, M,
Frelin C,
and
Vigne P.
The sodium/hydrogen exchange system in cardiac cells: its biochemical and pharmacological properties and its role in regulating internal concentrations of sodium and internal pH.
J Mol Cell Cardiol
17:
1929-1042,
1985.
18.
Little, PJ,
Neylon CB,
Farrelly CA,
Weissberg PL,
Cragoe EJ, Jr,
and
Bobik A.
Intracellular pH in vascular smooth muscle: regulation by sodium-hydrogen exchange and multiple sodium-dependent HCO
19.
Luscinskas, FW,
Cybulsky MI,
Kiely JM,
Peckins CS,
Davis VM,
and
Gimbrone MA.
Cytokine-activated human endothelial monolayers support enhanced neutrophil transmigration via a mechanism involving both endothelial-leukocyte adhesion molecule-1 and intercellular adhesion molecule-1.
J Immunol
146:
1617-1625,
1991[Abstract].
20.
Maddaford, TG,
and
Pierce GN.
Myocardial dysfunction is associated with activation of Na+/H+ exchange immediately during reperfusion.
Am J Physiol Heart Circ Physiol
273:
H2232-H2239,
1997
21.
Matsubara, H,
Kanasaki M,
Murasawa S,
Tsukaguti Y,
Nio Y,
and
Inada M.
Differential gene expression and regulation of angiotensin receptor subtypes in rat cardiac fibroblasts and cardiomyocytes in culture.
J Clin Invest
93:
1592-1601,
1994.
22.
Nishida, M,
Carley WW,
Gerritsen ME,
Ellingsen O,
Kelly RA,
and
Smith TW.
Isolation and characterization of human and rat cardiac microvascular endothelial cells.
Am J Physiol Heart Circ Physiol
264:
H639-H652,
1993
23.
Nishikawa, Y,
Ukida M,
Matsuo R,
Omori N,
and
Tsuji T.
Ca2+ influx initiates death of hepatocytes injured by activation of complement.
Liver
14:
200-205,
1994[Web of Science][Medline].
24.
Otani, H.
Role of calcium in the pathogenesis of myocardial reperfusion injury.
In: Pathophysiology of Reperfusion Injury, edited by Das DK.. Boca Raton, FL: CRC, 1993, p. 181-219.
25.
Piwnica-Worms, D,
Jacob R,
Shigeto N,
Horres R,
and
Lieberman M.
Na/H exchange in cultured chick heart cells: secondary stimulation of electrogenic transport during recovery from intracellular acidosis.
J Mol Cell Cardiol
18:
1109-1116,
1986[Web of Science][Medline].
26.
Rochitte, CE,
Lima JAC,
Bluemke DA,
Reeder SB,
McVeigh ER,
Furuta T,
Becker LC,
and
Melin JA.
Magnitude and time course of micro-vascular obstruction and tissue injury after acute myocardial infarction.
Circulation
98:
1006-1014,
1998
27.
Romson, JL,
Hook BG,
Kunkel SL,
Abrams CD,
Scork A,
and
Lucchesi BR.
Reduction of extent of ischemic myocardial injury by neutrophil depletion in the dog.
Circulation
67:
1016-1023,
1983
28.
Yamazaki, T,
Seko Y,
Tamatani T,
Miyasaka M,
Yagita H,
Okumura K,
Nagai R,
and
Yazaki Y.
Expression of intercellular adhesion molecule-1 in rat heart with ischemia/reperfusion and limitation of infarct size by treatment with antibodies against cell adhesion molecules.
Am J Pathol
143:
410-418,
1993[Abstract].
29.
Yoshida, H,
and
Karmazyn M.
Na+/H+ exchange inhibition attenuates hypertrophy and heart failure in 1-wk postinfarction rat myocardium.
Am J Physiol Heart Circ Physiol
278:
H300-H304,
2000
This article has been cited by other articles:
|
|
 |
|
  S. C. Peters and H. M. Piper Reoxygenation-induced Ca2+ rise is mediated via Ca2+ influx and Ca2+ release from the endoplasmic reticulum in cardiac endothelial cells Cardiovasc Res, January 1, 2007; 73(1): 164 - 171. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Muro, M. Mateescu, C. Gajewski, M. Robinson, V. R. Muzykantov, and M. Koval Control of intracellular trafficking of ICAM-1-targeted nanocarriers by endothelial Na+/H+ exchanger proteins Am J Physiol Lung Cell Mol Physiol, May 1, 2006; 290(5): L809 - L817. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. G. Zani and H. G. Bohlen Transport of extracellular L-arginine via cationic amino acid transporter is required during in vivo endothelial nitric oxide production Am J Physiol Heart Circ Physiol, October 1, 2005; 289(4): H1381 - H1390. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Vinten-Johansen and R. M. Mentzer Jr Attenuation of postcardioplegia injury with inhibitors of the sodium-hydrogen exchanger J. Thorac. Cardiovasc. Surg., November 1, 2003; 126(5): 1265 - 1267. [Full Text] [PDF]
|
|
|
|
|
|
T. Reffelmann and R. A. Kloner Is microvascular protection by cariporide and ischemic preconditioning causally linked to myocardial salvage? Am J Physiol Heart Circ Physiol, April 1, 2003; 284(4): H1134 - H1141. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. H. Nemeth, E. A. Deitch, Q. Lu, C. Szabo, and G. Hasko NHE blockade inhibits chemokine production and NF-kappa B activation in immunostimulated endothelial cells Am J Physiol Cell Physiol, August 1, 2002; 283(2): C396 - C403. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Avkiran and M. S. Marber Na+/h+ exchange inhibitors for cardioprotective therapy: progress, problems and prospects J. Am. Coll. Cardiol., March 6, 2002; 39(5): 747 - 753. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
, Vehicle (0.1% DMSO);
, 3 µmol/l cariporide; 
, 10 µmol/l
cariporide; 
, 30 µmol/l DMA; 
, 100 µmol/l DMA. Each symbol represents the mean ± SE of at least 6 experiments. *P < 0.05 and **P < 0.01 compared with vehicle.
