Abstract
This study is aimed to test the hypothesis, that short-term daily bouts of exercise alter the endothelial regulation of peripheral vascular resistance by nitric oxide. Rats ran on a treadmill once a day, 5 days a week, for an average of three weeks with gradually increasing intensity (EX), while a control group remained sedentary (SED). Dose dependent reductions in mean arterial blood pressure (resting MABP; SED: 120.0±3.4 and EX: 127.8±4.0 mm Hg) of pentobarbital anesthetized rats to intravenous endothelium independent dilator sodium nitroprusside (SNP; 0.6-3.0 μg/kg) were not different in EX and SED animals. In contrast, dose dependent reductions in MABP to endothelium dependent dilator acetylcholine (ACh) were significantly enhanced in EX compared to those in SED rats (at 0.5 and 1.0 μg/kg ACh: 60.3±2.4 and 66.5±1.8 vs 52.8±2.0 and 59.8±1.7 mmHg, respectively, pω-nitro-L-arginine (L-NNA, a nitric oxide synthase inhibitor) elicited a similar increase (∼30%) in the MABP in the two groups and eliminated the difference between ACh-induced blood pressure lowering responses in EX and SED rats (at 0.5 and 1.0 μg/kg ACh: 44.6±4.7 and 56.3±4.4 vs 50.9±4.5 and 59.4±3.6 mm Hg, respectively). Thus, we suggest that the enhanced acetylcholine-induced decrease in systemic blood pressure following regular daily exercise is primarily due to the augmented synthesis of nitric oxide in the endothelium of peripheral vasculature. This change in the function of endothelium could be important in the adaptation of circulation to exercise training.
| Original language | English |
|---|---|
| Pages (from-to) | 127-138 |
| Number of pages | 12 |
| Journal | Acta Physiologica Hungarica |
| Volume | 87 |
| Issue number | 2 |
| Publication status | Published - 2000 |
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Keywords
- Exercise
- L-NNA
- Nitric oxide
- Peripheral resistance
- Rats
- Sodium nitroprusside
ASJC Scopus subject areas
- Physiology
Cite this
Regular exercise enhances blood pressure lowering effect of acetylcholine by increased contribution of nitric oxide. / Dörnyei, Gabriella; Monos, E.; Kaley, G.; Koller, Á.
In: Acta Physiologica Hungarica, Vol. 87, No. 2, 2000, p. 127-138.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Regular exercise enhances blood pressure lowering effect of acetylcholine by increased contribution of nitric oxide
AU - Dörnyei, Gabriella
AU - Monos, E.
AU - Kaley, G.
AU - Koller, Á
PY - 2000
Y1 - 2000
N2 - This study is aimed to test the hypothesis, that short-term daily bouts of exercise alter the endothelial regulation of peripheral vascular resistance by nitric oxide. Rats ran on a treadmill once a day, 5 days a week, for an average of three weeks with gradually increasing intensity (EX), while a control group remained sedentary (SED). Dose dependent reductions in mean arterial blood pressure (resting MABP; SED: 120.0±3.4 and EX: 127.8±4.0 mm Hg) of pentobarbital anesthetized rats to intravenous endothelium independent dilator sodium nitroprusside (SNP; 0.6-3.0 μg/kg) were not different in EX and SED animals. In contrast, dose dependent reductions in MABP to endothelium dependent dilator acetylcholine (ACh) were significantly enhanced in EX compared to those in SED rats (at 0.5 and 1.0 μg/kg ACh: 60.3±2.4 and 66.5±1.8 vs 52.8±2.0 and 59.8±1.7 mmHg, respectively, pω-nitro-L-arginine (L-NNA, a nitric oxide synthase inhibitor) elicited a similar increase (∼30%) in the MABP in the two groups and eliminated the difference between ACh-induced blood pressure lowering responses in EX and SED rats (at 0.5 and 1.0 μg/kg ACh: 44.6±4.7 and 56.3±4.4 vs 50.9±4.5 and 59.4±3.6 mm Hg, respectively). Thus, we suggest that the enhanced acetylcholine-induced decrease in systemic blood pressure following regular daily exercise is primarily due to the augmented synthesis of nitric oxide in the endothelium of peripheral vasculature. This change in the function of endothelium could be important in the adaptation of circulation to exercise training.
AB - This study is aimed to test the hypothesis, that short-term daily bouts of exercise alter the endothelial regulation of peripheral vascular resistance by nitric oxide. Rats ran on a treadmill once a day, 5 days a week, for an average of three weeks with gradually increasing intensity (EX), while a control group remained sedentary (SED). Dose dependent reductions in mean arterial blood pressure (resting MABP; SED: 120.0±3.4 and EX: 127.8±4.0 mm Hg) of pentobarbital anesthetized rats to intravenous endothelium independent dilator sodium nitroprusside (SNP; 0.6-3.0 μg/kg) were not different in EX and SED animals. In contrast, dose dependent reductions in MABP to endothelium dependent dilator acetylcholine (ACh) were significantly enhanced in EX compared to those in SED rats (at 0.5 and 1.0 μg/kg ACh: 60.3±2.4 and 66.5±1.8 vs 52.8±2.0 and 59.8±1.7 mmHg, respectively, pω-nitro-L-arginine (L-NNA, a nitric oxide synthase inhibitor) elicited a similar increase (∼30%) in the MABP in the two groups and eliminated the difference between ACh-induced blood pressure lowering responses in EX and SED rats (at 0.5 and 1.0 μg/kg ACh: 44.6±4.7 and 56.3±4.4 vs 50.9±4.5 and 59.4±3.6 mm Hg, respectively). Thus, we suggest that the enhanced acetylcholine-induced decrease in systemic blood pressure following regular daily exercise is primarily due to the augmented synthesis of nitric oxide in the endothelium of peripheral vasculature. This change in the function of endothelium could be important in the adaptation of circulation to exercise training.
KW - Exercise
KW - L-NNA
KW - Nitric oxide
KW - Peripheral resistance
KW - Rats
KW - Sodium nitroprusside
UR - http://www.scopus.com/inward/record.url?scp=0342420693&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0342420693&partnerID=8YFLogxK
M3 - Article
C2 - 11205960
AN - SCOPUS:0342420693
VL - 87
SP - 127
EP - 138
JO - Physiology International
JF - Physiology International
SN - 2498-602X
IS - 2
ER -