|
|
||||||||
1 Department of Physiology, New York Medical College, Valhalla, New York 10595; and 2 University of Texas Southwestern Medical Center, Dallas, Texas 75235
| |
ABSTRACT |
|---|
|
|
|---|
Flow-induced dilation of
gracilis muscle arterioles was examined in both genders of control rats
and rats chronically treated with
N
-nitro-L-arginine methyl ester
(L-NAME). After L-NAME treatment (4 wk),
systolic blood pressure was significantly increased compared with
control, whereas the plasma concentration of nitrate/nitrite was
significantly reduced. Isolated and pressurized arterioles dilated
significantly in response to increases in flow (0-25 µl/min). Flow-induced dilation was comparable in arterioles of control and
L-NAME-treated rats but was significantly greater in female than in male rats. L-NAME + indomethacin, which
abolished flow-induced dilation in arterioles of male control rats,
inhibited the dilation by only ~75% in female control rats. The
residual portion of the response was eliminated by additional
administration of miconazole, an inhibitor of cytochrome
P-450. Indomethacin did not affect the dilation in female
L-NAME-treated rats but completely inhibited the response
in male L-NAME-treated rats. The indomethacin-insensitive, flow-induced dilation in female L-NAME-treated
arterioles was abolished by miconazole,
6-(2-proparglyoxyphenyl)hexanoic acid, or charybdotoxin. Thus an
augmented release of endothelial prostaglandins accounts for the
preserved flow-induced dilation in arterioles of male rats, whereas a
metabolite of cytochrome P-450 is responsible for the
maintenance of flow-induced dilation in female rats, suggesting important differences in the adaptation of the endothelium of arterioles from male and female rats to the lack of nitric oxide (NO) synthesis.
NO synthesis; hyperpolarizing factor; cytochrome P-450 metabolites; potassium channels
| |
INTRODUCTION |
|---|
|
|
|---|
THE ENDOTHELIUM PLAYS AN IMPORTANT role in the regulation of vascular tone via release of dilator mediators, including nitric oxide (NO), prostaglandins, and endothelium-derived hyperpolarizing factor (EDHF), the latter generally being characterized as a metabolite of arachidonic acid via cytochrome P-450 (CYP) epoxygenase (6, 13, 18, 19). One of the important local factors governing arteriolar tone is wall shear stress, which is the primary stimulus for release of endothelial NO, as well as prostaglandins, in vivo (14, 15).
There is but scant evidence regarding the release of EDHF in response to increases in shear stress elicited by flow, especially because its synthesis is believed to be inhibited by the other two endothelial mediators released to flow (1, 24). Indeed, there is increasing evidence suggesting a feedback inhibition on EDHF production by NO and/or prostaglandins (2, 20, 24), as well as potential interactions among these three endothelial mediators (16). Upregulation of one system in response to a suppression or deficiency of the others has also been demonstrated (3, 4, 20). Our previous studies have shown that, in skeletal muscle arterioles, flow-induced dilation in male wild-type (WT) mice is mediated by endothelial NO and prostaglandins, whereas it is mediated exclusively by prostaglandins in arterioles of male endothelial NO synthase gene-deficient (eNOS-KO) mice (22). In the same vessels isolated from female WT mice, EDHF, together with prostaglandins, participates in the mediation of flow-induced dilation when NO is acutely inhibited; however, EDHF is solely responsible for the maintenance of this response in female eNOS-KO mice (9).
The question, therefore, arose as to whether the gender-specific
compensation involving flow-induced dilation in response to NO
deficiency is a universal phenomenon or simply a species-specific response. In addition, whether the effects of a short-term adaptation to the absence of NO synthesis are any different from those caused by a
genetic lack of eNOS is of interest. Accordingly, we designed experiments to be conducted on arterioles of male and female rats that
were chronically treated with
N
-nitro-L-arginine methyl ester
(L-NAME), an inhibitor of the synthesis of NO.
| |
METHODS |
|---|
|
|
|---|
Animals. Twelve-week-old Wistar rats (Charles River Laboratories, Wilmington, MA) were divided into four groups: control untreated male, L-NAME-treated male, untreated female, and L-NAME-treated female rats. Rats received L-NAME in the drinking water (50 mg/100 ml) for 4 wk. Age-matched normal male and female rats drinking tap water alone were studied concomitantly. All protocols were approved by the Institutional Animal Care and Use Committee of New York Medical College and conform to the guidelines of the National Institutes of Health and the American Physiological Society for the use and care of laboratory animals.
Experimental procedures. Systolic blood pressure (SBP) and heart rate were monitored every 3 days after the start of treatment by using the tail-cuff method. Rats were anesthetized with pentobarbital sodium (Nembutal, 50 mg/kg ip). Experiments were conducted on isolated gracilis muscle arterioles of all rats. The dissection of muscle and isolation of vessels have been described previously (10, 14). Changes in the diameter of arterioles in response to increases in flow were studied at 80 mmHg perfusion pressure. Perfusate flow was increased from 0 to 25 µl/min in 5 µl/min steps. After control experiments, inhibitors were administered in the perfusate for 30 min before and during the experimental protocols.
In the first series of experiments, the role of NO or prostaglandins in the mediation of flow-induced dilation was assessed by using L-NAME (10
4 M) and indomethacin (Indo,
10
5 M), inhibitors of NO synthase and cyclooxygenase,
respectively. After control flow-diameter curves were obtained, an
inhibitor was administered alone or in combination with the other
before the flow-diameter relationships were once more assessed.
In the second series of experiments, the role and interaction of
metabolites of cytochrome P-450 (CYP) and eNOS on
flow-induced dilations were assessed by using miconazole (MCZ, 2 × 10
6 M), an inhibitor of CYP epoxygenase, and
L-NAME. After control experiments, MCZ or
L-NAME was administered before the experiments were
repeated. Then flow-induced responses were studied once more in the
additional presence of the other inhibitor. In a separate group of
experiments, the effect of metabolites of CYP on flow-induced dilation
in arterioles of L-NAME-treated female rats was confirmed further by using 6-(2-proparglyoxyphenyl)hexanoic acid (PPOH, 10
5 M), which is thought to be a more specific inhibitor
of CYP epoxygenase (23).
In the third series of experiments, the contribution of EDHF to
flow-induced responses was again evaluated by performing the experiments before and after abluminal administration of charybdotoxin (ChTX, 2 × 10
8 M), a blocker of
Ca2+-dependent K+ channels. These channels are
thought to be activated by EDHF, causing hyperpolarization of vascular
smooth muscle and vessel dilation.
Passive diameter. At the conclusion of each experiment, the suffusion solution was changed to a Ca2+-free solution containing 1 mM EGTA. Vessels were incubated for 10 min to reach maximal diameter at 80 mmHg perfusion pressure.
Measurement of plasma nitrate/nitrite.
After the muscle had been excised, blood (5 ml) was withdrawn from the
abdominal aorta with a 10-ml syringe containing 0.1 ml of heparin
sodium (1,000 U/ml). The blood sample was centrifuged immediately
(3,000 rpm at 4°C for 20 min) to obtain the plasma, which was then
filtered through a 10,000-mol wt cutoff filter (NANOSEP, Fisher) to
remove Hb. The plasma was kept at
80°C for later measurement of
plasma nitrite/nitrate (NO2/NO3) concentration (25) by fluorometric assay.
Chemicals.
All chemicals were obtained from Sigma (St. Louis, MO). PPOH was
dissolved in ethanol at 10
2 M and further diluted with
physiological salt solution (PSS). L-NAME and ChTX were
dissolved in saline. Indo and MCZ were dissolved in DMSO at
10
1 and 10
2 M for Indo and MCZ,
respectively, and further diluted with PSS. The highest concentration
of DMSO in the chamber was 0.1% (vol/vol), which had no effect on
vessel tone.
Calculations and statistics. Passive diameter (PD) was used to assess the active tone (%PD) generated by arterioles in response to intravascular pressure and to normalize the changes in diameter in response to increases in flow in each vessel. Values are means ± SE; n is the number of rats. Statistical significance was calculated by repeated-measures of ANOVA followed by the Tukey-Kramer multiple-comparison test. Student's t-test was also used, as appropriate. Significance level was taken at P < 0.05.
| |
RESULTS |
|---|
|
|
|---|
Table 1 shows the changes in SBP,
heart rate, and plasma concentrations of
NO2/NO3 in four groups of rats. SBP was
significantly increased and heart rate was correspondingly reduced in
L-NAME-treated rats compared with untreated rats
(P < 0.05). Also, plasma concentration of
NO2/NO3 was significantly reduced after
L-NAME treatment (P < 0.05).
|
Characteristics of arterioles of gracilis muscle from the four groups
of rats studied are summarized in Table
2. PDs were significantly smaller in
arterioles of L-NAME-treated than untreated rats, whereas
active diameters and basal tone, expressed as percentage of PD, were
comparable in vessels from rats of the same gender. On the other hand,
basal arteriolar tone in female rats was significantly attenuated
compared with that in male rats (P < 0.05).
|
Increasing flow from 0 to 25 µl/min elicited significant increases in
diameter of arterioles from all four groups of rats (Fig.
1). The magnitude of flow-induced
dilation of arterioles was comparable in untreated and treated rats of
the same gender but was significantly greater in female than in male
rats (~89.8 ± 1.3 vs. 73.9 ± 1.3% at 25 µl/min),
confirming our previous findings (11).
|
Arterioles of male rats.
The endothelial mediators responsible for the mediation of flow-induced
dilation in arterioles of male rats are summarized in Fig.
2, showing that in untreated rats
(A), Indo or L-NAME alone inhibited flow-induced
dilation by ~50%. Combined administration of both inhibitors
abolished the responses. In rats treated chronically with
L-NAME (Fig. 2B), Indo eliminated the dilator
responses to flow, revealing a solely prostaglandin-mediated
flow-induced dilation as a consequence of L-NAME treatment.
|
Arterioles of female rats.
The endothelial mediators responsible for the mediation of flow-induced
dilation in arterioles of female rats are summarized in Figs.
3 and 4. A
prostaglandin-mediated portion of flow-induced dilation in arterioles
of untreated female rats was demonstrated by the fact that Indo
inhibited the responses by ~50% whether Indo was administered first
or last among the inhibitors used (Fig. 3). The roles of NO and
metabolites of CYP in the mediation of flow-induced dilation in vessels
of untreated female rats were also assessed by using L-NAME
and MCZ. The Indo-resistant portion of the response was partially
inhibited by L-NAME or MCZ after L-NAME (Fig.
3, top and middle). On the other hand, unlike
L-NAME, MCZ alone did not affect the Indo-resistant portion
of the response, which, however, was eliminated by additional
administration of L-NAME (Fig. 3, bottom),
suggesting an interaction between NO and metabolites of CYP.
|
|
| |
DISCUSSION |
|---|
|
|
|---|
The present study demonstrates a gender-specific adaptation to the lack of NO in the mediation of endothelium-dependent flow-induced dilations in rat gracilis muscle arterioles. It also shows that although NO and prostaglandins participate equally in the mediation of flow-dependent responses in control rats of both genders, after chronic treatment with L-NAME, prostaglandins account solely for this response in vessels of male rats and EDHF in vessels of female rats. Also, EDHF contributes partially to the mediation of flow-induced dilation when NO synthesis is acutely inhibited in female control rats. These findings are consistent with our previous studies in WT and eNOS-KO mice (9, 22). The congruence between the present and our previous studies reveals that a deficiency of eNOS-derived NO activates gender-specific signal transduction pathways.
It was reported previously that the cardiovascular system adapts to an acute inhibition of NO synthesis in a manner that is different from that observed with a chronic lack of NO (5). Also our previous studies demonstrated that, in skeletal muscle arterioles of eNOS-KO mice, endothelial cells adapt to the chronic lack of NO and maintain a normal or close-to-normal response to shear stress by upregulation of the synthesis of other mediators, which, however, operate in a heterogeneous fashion dependent on gender (9, 22). Given that compensatory mechanisms may play an important role in the maintenance of cardiovascular function and that sex hormones may participate in the control of this compensation, it was of interest to define the nature of the mechanisms by which vessels are capable of responding normally to flow/shear stress in the absence of NO. To this end, flow-induced dilation and the nature of the endothelial factors mediating this response were investigated in gracilis muscle arterioles of rats of both genders treated chronically with L-NAME.
SBP was significantly enhanced, resulting in a reflex attenuation of heart rate in L-NAME-treated rats. Also, plasma concentrations of NO2/NO3 were significantly reduced after chronic L-NAME treatment (Table 1). The PD of arterioles of L-NAME-treated rats was significantly smaller than that of untreated littermates, a finding similar to that in eNOS-KO mice (9, 22), whereas the active diameters and the basal tone of vessels were comparable in the vessels of the two groups (Table 2). In addition, the results showing attenuated basal tone (Table 2) and enhanced flow-induced dilation (Fig. 1) in arterioles of female compared with male rats are consistent with our previous findings (10-12) showing that the greater basal and stimulated release of endothelial NO, triggered by the presence of estrogen, is responsible for these differences. Interestingly, in the present study, the reduced basal tone and greater flow-induced dilation in female than in male rats seem not to be purely NO dependent, since they are also present in L-NAME-treated littermates. On the other hand, the similar magnitude of flow-induced dilation in treated and untreated rats of the same gender (Fig. 1) further supports our hypothesis that arterioles of skeletal muscle are able to compensate for the absence of NO to maintain dilator responses to shear stress.
Adaptation of arterioles of male rats. Our present findings are similar to those we reported previously (14) showing that endothelium-derived NO and prostaglandins are coreleased in gracilis muscle arterioles of untreated male rats in response to increases in flow, that endothelium-derived NO and prostaglandins are responsible for the ensuing vasodilation, and that inhibition of NO or prostaglandin synthesis reduces the dilation by ~50%. Combination of both inhibitors eliminated the responses (Fig. 2A). In contrast, in arterioles of male rats treated chronically with L-NAME, Indo completely eliminated flow-induced dilation, indicating that the response is solely mediated by enhanced release of dilator prostaglandins (Fig. 2B), a finding that corresponds to that observed in the same vessels of male eNOS-KO mice (22). Recently, we demonstrated that this compensatory upregulation of prostaglandin synthesis most likely involves inducible cyclooxygenase (unpublished observations). In keeping with the present findings, an upregulation of cyclooxygenase activity, as a consequence of chronic NO deficiency, has also been demonstrated in the dog coronary (3, 21) and rat mesenteric circulations (8).
Adaptation of arterioles of female rats. As for the endothelial factors responsible for the mediation of flow-induced responses in arterioles of female mice, results shown in Fig. 3 indicate that in untreated rats, apart from the coparticipation of NO and prostaglandins, CYP metabolites contribute, in part, to the mediation of the responses, as indicated by the inhibitory effect of MCZ on the dilations. However, such a role for CYP metabolites was observed only in the presence of L-NAME, since MCZ alone did not affect the responses (Fig. 3, bottom). Unlike MCZ, either L-NAME or Indo alone significantly inhibited flow-induced dilation (Fig. 3, top and middle), indicating that NO and prostaglandins are the primary mediators of this response in normal conditions. The absence of NO after the acute administration of L-NAME activates CYP, eliciting EDHF formation, which then contributes to the mediation of flow-dependent dilation. A similar effect of a NO donor on agonist-induced EDHF release from porcine (1, 2) and canine coronary arteries (20) was also reported.
In female rats treated chronically with L-NAME (Fig. 4), MCZ or PPOH alone abolished flow-induced dilation, indicating a solely CYP metabolite-dependent response, unaffected by inhibition of cyclooxygenase (Fig. 4A). Furthermore, the dilation is completely inhibited by ChTX (Fig. 4B), suggesting further that the CYP-mediated dilation to flow is indeed dependent on hyperpolarization of vascular smooth muscle, via activation of Ca2+-sensitive K+ channels (6). These results, together with those observed in eNOS-KO mice, may well form the basis of the gender-dependent mechanisms by which compensation for the lack of endothelial NO occurs in resistance vessels. Regarding the relationships between EDHF and female hormones, previous studies have provided some evidence suggesting that estrogen enhances the contribution of EDHF in the mediation of agonist-induced vasodilation (17) and smooth muscle membrane hyperpolarization (7). Further studies are necessary to establish the possible role(s) of specific hormones that are responsible for the activation of endothelial pathways leading to the synthesis of NO, prostaglandins, and EDHF in the two genders. In conclusion, we demonstrated that, in skeletal muscle arterioles of male and female rats, NO and prostaglandins are the primary mediators of flow-induced dilation in control conditions. When NO synthesis is blocked acutely, EDHF participates in the responses of vessels of female rats. In arterioles of male rats chronically treated with L-NAME, prostaglandins are solely responsible for the preserved flow-induced dilation, whereas in vessels of L-NAME-treated female rats, this response is exclusively mediated by EDHF. These data, together with our previous findings in eNOS-KO mice, support our hypothesis that compensatory mechanisms in arterioles evoked by the absence of NO are indeed gender dependent in nature, through which enhanced contribution of endothelial mediators other than NO contribute to the maintenance of shear stress-sensitive regulation of skeletal muscle arterioles and, consequently, peripheral resistance.| |
ACKNOWLEDGEMENTS |
|---|
We appreciate the excellent secretarial assistance of Miriam Nunez and Dana M. Spencer.
| |
FOOTNOTES |
|---|
This study was supported by National Heart, Lung, and Blood Institute Grants HL-43023 and HL-46813, and American Heart Association Grant 9930244N.
Address for reprint requests and other correspondence: G. Kaley, Dept. of Physiology, New York Medical College, Valhalla, NY 10595 (E-mail: Gabor_Kaley{at}NYMC.edu).
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 7 December 2000; accepted in final form 10 January 2001.
| |
REFERENCES |
|---|
|
|
|---|
1.
Bauersachs, J,
Popp R,
and
Busse R.
Nitric oxide and endothelium-derived hyperpolarizing factors: formation and interactions.
Prostaglandins Leukot Essent Fatty Acids
57:
439-446,
1997[Web of Science][Medline].
2.
Bauersachs, J,
Popp R,
Hecher M,
Sauer E,
Fleming I,
and
Busse R.
Nitric oxide attenuates the release of endothelium-derived hyperpolarizing factor.
Circulation
94:
3341-3347,
1996
3.
Beverelli, F,
Bea ML,
Puybasset L,
Giudicelli JF,
and
Berdeaux A.
Chronic inhibition of NO synthase enhances the production of prostacyclin in coronary arteries through upregulation of the cyclooxygenase type I isoform.
Fundam Clin Pharmacol
11:
252-259,
1997[Web of Science][Medline].
4.
Doni, MG,
Whittle BJR,
Palmer RMJ,
and
Moncada S.
Actions of nitric oxide on the release of prostacyclin from bovine endothelial cells in culture.
Eur J Pharmacol
15:
19-25,
1988.
5.
Gödecke, A,
Decking UKM,
Ding Z,
Hirchenhan J,
Bidmon H-J,
Gödecke S,
and
Schrader J.
Coronary hemodynamics in endothelial NO synthase knockout mice.
Circ Res
82:
186-194,
1998
6.
Harder, DR,
Campbell WB,
and
Roman RJ.
Role of cytochrome P-450 enzymes and metabolites of arachidonic acid in the control of vascular tone.
J Vasc Res
32:
79-92,
1995[Web of Science][Medline].
7.
Harder, DR,
and
Coulson PB.
Estrogen receptor and effects of estrogen on membrane electrical properties of coronary vascular smooth muscle.
J Cell Physiol
100:
375-382,
1979[Web of Science][Medline].
8.
Henrion, D,
Dechaux E,
Dowell FJ,
Maclour J,
Samuel JL,
Levy BI,
and
Michel JB.
Alteration of flow-induced dilation in mesenteric resistance arteries of L-NAME treated rats and its partial association with induction of cyclooxygenase-2.
Br J Pharmacol
121:
83-90,
1997[Web of Science][Medline].
9.
Huang, A,
Sun D,
Carroll MA,
Jiang H,
Smith CJ,
Connetta JA,
Falck JR,
Shesely EG,
Koller A,
and
Kaley G.
EDHF is released to flow in skeletal muscle arterioles of female eNOS-KO mice.
Am J Physiol Heart Circ Physiol
280:
H000-H000,
2001.
10.
Huang, A,
Sun D,
Koller A,
and
Kaley G.
Gender difference in myogenic tone of rat arterioles is due to estrogen-induced enhanced release of NO.
Am J Physiol Heart Circ Physiol
272:
H1804-H1809,
1997
11.
Huang, A,
Sun D,
Koller A,
and
Kaley G.
Gender difference in flow-induced dilation and regulation of shear stress: role of estrogen and nitric oxide.
Am J Physiol Regulatory Integrative Comp Physiol
275:
R1571-R1577,
1998
12.
Huang, A,
Sun D,
Koller A,
and
Kaley G.
17
-Estradiol restores endothelial nitric oxide release to shear stress in arterioles of male hypertensive rats.
Circulation
10:
94-100,
2000.
13.
Koller, A,
and
Kaley G.
Endothelial control of shear stress and resistance in skeletal muscle microcirculation.
In: Flow Dependent Regulation of Vascular Function, edited by Bevan JA,
Kaley G,
and Rubanyi GM.. New York: Oxford University Press, 1994, p. 236-260.
14.
Koller, A,
Sun D,
Huang A,
and
Kaley G.
Corelease of nitric oxide and prostaglandins mediates flow-dependent dilation of rat gracilis muscle arterioles.
Am J Physiol Heart Circ Physiol
266:
H326-H332,
1994.
15.
Koller, A,
Sun D,
and
Kaley G.
Role of shear stress and endothelial prostaglandins in flow- and viscosity-induced dilation of arterioles in vitro.
Circ Res
72:
1276-1284,
1993
16.
Lamping, KG,
Nuno DW,
Shesely EG,
Maeda N,
and
Faraci FM.
Vasodilator mechanisms in the coronary circulation of endothelial nitric oxide synthase-deficient mice.
Am J Physiol Heart Circ Physiol
279:
H1906-H1912,
2000
17.
McCulloch, AI,
and
Randall MD.
Sex differences in the relative contributions of nitric oxide and EDHF to agonist-stimulated endothelium-dependent relaxations in the rat isolated mesenteric arterial bed.
Br J Pharmacol
123:
1700-1706,
1998[Web of Science][Medline].
18.
Miura, H,
Liu Y,
and
Gutterman DD.
Human coronary arteriolar dilation to bradykinin depends on membrane hyperpolarization. Contribution of nitric oxide and Ca2+-activated K+ channels.
Circulation
99:
3132-3138,
1999
19.
Moncada, S,
Palmer RMJ,
and
Higgs EA.
Nitric oxide: physiology, pathophysiology, and pharmacology.
Pharmacol Rev
43:
109-142,
1991[Web of Science][Medline].
20.
Nishikawa, Y,
Stepp DW,
and
Chilian WM.
Nitric oxide exerts feedback inhibition on EDHF-induced coronary arteriolar dilation in vivo.
Am J Physiol Heart Circ Physiol
279:
H459-H465,
2000
21.
Puybasset, L,
Bea ML,
Ghaleh B,
Giudicelli JF,
and
Berdeaux A.
Coronary and systemic hemodynamic effects of sustained inhibition of nitric oxide synthesis in conscious dogs: evidence for cross talk between nitric oxide and cyclooxygenase in coronary vessels.
Circ Res
79:
343-357,
1996
22.
Sun, D,
Huang A,
Smith CJ,
Stackpole CJ,
Connetta JA,
Shesely EG,
Koller A,
and
Kaley G.
Enhanced release of prostaglandins contributes to flow-induced arteriolar dilation in eNOS knockout mice.
Circ Res
85:
288-293,
1999
23.
Wang, M-H,
Brand-Schieber E,
Zand BA,
Nguyen X,
Falck JR,
Balu N,
and
Schwartzman ML.
Cytochrome P450-derived arachidonic acid metabolism in the rat kidney: characterization of selective inhibitors.
J Pharmacol Exp Ther
284:
966-973,
1998
24.
Yajima, K,
Nishiyama M,
Yamamoto Y,
and
Suzuki H.
Inhibition of endothelium-dependent hyperpolarization by endothelial prostanoids in guinea-pig coronary artery.
Br J Pharmacol
126:
1-10,
1999[Web of Science][Medline].
25.
Zeballos, GA,
Bernstein RD,
Thompson CI,
Forfia PR,
Seyedi N,
Shen W,
Kaminski PM,
Wolin MS,
and
Hintze TH.
Pharmacodynamics of plasma nitrate/nitrite as an indication of nitric oxide formation in conscious dogs.
Circulation
91:
2982-2988,
1995
This article has been cited by other articles:
![]() |
R. M. McAllister, S. C. Newcomer, E. R. Pope, J. R. Turk, and M. H. Laughlin Effects of chronic nitric oxide synthase inhibition on responses to acute exercise in swine J Appl Physiol, January 1, 2008; 104(1): 186 - 197. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. E. Bearden Advancing age produces sex differences in vasomotor kinetics during and after skeletal muscle contraction Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1274 - R1279. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Sun, C. Yan, A. Jacobson, H. Jiang, M. A. Carroll, and A. Huang Contribution of epoxyeicosatrienoic acids to flow-induced dilation in arteries of male ER{alpha} knockout mice: role of aromatase Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1239 - R1246. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Ingram, S. C. Newcomer, E. M. Price, K. E. Eklund, R. M. McAllister, and M. H. Laughlin Chronic nitric oxide synthase inhibition blunts endothelium-dependent function of conduit coronary arteries, not arterioles Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H2798 - H2808. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Phillips, O. A. Hatoum, and D. D. Gutterman The mechanism of flow-induced dilation in human adipose arterioles involves hydrogen peroxide during CAD Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H93 - H100. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Sun, H. Liu, C. Yan, A. Jacobson, C. Ojaimi, A. Huang, and G. Kaley COX-2 contributes to the maintenance of flow-induced dilation in arterioles of eNOS-knockout mice Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1429 - H1435. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. d'Agostino, V. Labinskyy, V. Lionetti, M. P. Chandler, B. Lei, K. Matsuo, M. Bellomo, X. Xu, T. H. Hintze, W. C. Stanley, et al. Altered cardiac metabolic phenotype after prolonged inhibition of NO synthesis in chronically instrumented dogs Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1721 - H1726. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Liu, A. H. Bubolz, Y. Shi, P. J. Newman, D. K. Newman, and D. D. Gutterman Peroxynitrite reduces the endothelium-derived hyperpolarizing factor component of coronary flow-mediated dilation in PECAM-1-knockout mice Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2006; 290(1): R57 - R65. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Miller, A. A. Hislop, P. J. Vallance, and S. G. Haworth Deletion of the eNOS gene has a greater impact on the pulmonary circulation of male than female mice Am J Physiol Lung Cell Mol Physiol, August 1, 2005; 289(2): L299 - L366. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Hemmings, S. J. Williams, and S. T. Davidge Increased myogenic tone in 7-month-old adult male but not female offspring from rat dams exposed to hypoxia during pregnancy Am J Physiol Heart Circ Physiol, August 1, 2005; 289(2): H674 - H682. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Huang, D. Sun, A. Jacobson, M. A. Carroll, J. R. Falck, and G. Kaley Epoxyeicosatrienoic Acids Are Released to Mediate Shear Stress-Dependent Hyperpolarization of Arteriolar Smooth Muscle Circ. Res., February 18, 2005; 96(3): 376 - 383. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. A. Hatoum, D. G. Binion, H. Miura, G. Telford, M. F. Otterson, and D. D. Gutterman Role of hydrogen peroxide in ACh-induced dilation of human submucosal intestinal microvessels Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H48 - H54. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Funk, G. Endler, R. Freitag, J. Wojta, K. Huber, C. Mannhalter, and R. Sunder-Plassmann CYP2C9*2 and CYP2C9*3 Alleles Confer a Lower Risk for Myocardial Infarction Clin. Chem., December 1, 2004; 50(12): 2395 - 2398. [Full Text] [PDF] |
||||
![]() |
J. Rogers and D. D. Sheriff Role of estrogen in nitric oxide- and prostaglandin-dependent modulation of vascular conductance during treadmill locomotion in rats J Appl Physiol, August 1, 2004; 97(2): 756 - 763. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Phillips, I. Drenjancevic-Peric, J. C. Frisbee, and J. H. Lombard Chronic AT1 receptor blockade alters mechanisms mediating responses to hypoxia in rat skeletal muscle resistance arteries Am J Physiol Heart Circ Physiol, August 1, 2004; 287(2): H545 - H552. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. G. Lamping, J. Wess, Y. Cui, D. W. Nuno, and F. M. Faraci Muscarinic (M) Receptors in Coronary Circulation: Gene-Targeted Mice Define the Role of M2 and M3 Receptors in Response to Acetylcholine Arterioscler Thromb Vasc Biol, July 1, 2004; 24(7): 1253 - 1258. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Huang, D. Sun, Z. Wu, C. Yan, M. A. Carroll, H. Jiang, J. R. Falck, and G. Kaley Estrogen Elicits Cytochrome P450--Mediated Flow-Induced Dilation of Arterioles in NO Deficiency: Role of PI3K-Akt Phosphorylation in Genomic Regulation Circ. Res., February 6, 2004; 94(2): 245 - 252. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. P. McKee, D. A. Van Riper, C. A. Davison, and H. A. Singer Gender-dependent modulation of alpha 1-adrenergic responses in rat mesenteric arteries Am J Physiol Heart Circ Physiol, May 1, 2003; 284(5): H1737 - H1743. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. H. Lane Diabetic kidney disease: impact of puberty Am J Physiol Renal Physiol, October 1, 2002; 283(4): F589 - F600. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. G. Schrage, C. R. Woodman, and M. H. Laughlin Mechanisms of flow and ACh-induced dilation in rat soleus arterioles are altered by hindlimb unweighting J Appl Physiol, March 1, 2002; 92(3): 901 - 911. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Huang, Y. Wu, D. Sun, A. Koller, and G. Kaley Effect of estrogen on flow-induced dilation in NO deficiency: role of prostaglandins and EDHF J Appl Physiol, December 1, 2001; 91(6): 2561 - 2566. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. B. Campbell and D. R. Harder Prologue: EDHF-what is it? Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2413 - H2416. [Full Text] [PDF] |
||||
![]() |
A. Huang, D. Sun, M. A. Carroll, H. Jiang, C. J. Smith, J. A. Connetta, J. R. Falck, E. G. Shesely, A. Koller, and G. Kaley EDHF mediates flow-induced dilation in skeletal muscle arterioles of female eNOS-KO mice Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2462 - H2469. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |