Abstract
In the present investigation we examined the role of ATP-sensitive potassium (K ATP ) channel activity in modulating carotid baroreflex (CBR)-induced vasoconstriction in the vasculature of the leg. The CBR control of mean arterial pressure (MAP) and leg vascular conductance (LVC) was determined in seven subjects (25 ± 1 years, mean ± S.E.M.) using the variable-pressure neck collar technique at rest and during one-legged knee extension exercise. The oral ingestion of glyburide (5 mg) did not change mean arterial pressure (MAP at rest (86 versus 89 mmHg, P > 0.05), but did appear to increase MAP during exercise (87 versus 92 mmHg, P = 0.053). However, the CBR-MAP function curves were similar at rest before and after glyburide ingestion. The CBR-mediated decrease in LVC observed at rest (∼39%) was attenuated during exercise in the exercising leg (∼15%, P < 0.05). Oral glyburide ingestion partially restored CBR-mediated vasoconstriction in the exercising leg (∼40% restoration, P < 0.05) compared to control exercise. These findings indicate that K ATP channel activity modulates sympathetic vasoconstriction in humans and may prove to be an important mechanism by which functional sympatholysis operates in humans during exercise.
| Original language | English |
|---|---|
| Pages (from-to) | 273-282 |
| Number of pages | 10 |
| Journal | Journal of Physiology |
| Volume | 561 |
| Issue number | 1 |
| DOIs | |
| State | Published - 15 Nov 2004 |
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Inhibition of K ATP channel activity augments baroreflex-mediated vasoconstriction in exercising human skeletal muscle . / Keller, David Melvin; Ogoh, Shigehiko; Greene, Shane; Yurvati, Albert; Raven, Peter B.
In: Journal of Physiology, Vol. 561, No. 1, 15.11.2004, p. 273-282.Research output: Contribution to journal › Article
TY - JOUR
T1 - Inhibition of K ATP channel activity augments baroreflex-mediated vasoconstriction in exercising human skeletal muscle
AU - Keller, David Melvin
AU - Ogoh, Shigehiko
AU - Greene, Shane
AU - Yurvati, Albert
AU - Raven, Peter B.
PY - 2004/11/15
Y1 - 2004/11/15
N2 - In the present investigation we examined the role of ATP-sensitive potassium (K ATP ) channel activity in modulating carotid baroreflex (CBR)-induced vasoconstriction in the vasculature of the leg. The CBR control of mean arterial pressure (MAP) and leg vascular conductance (LVC) was determined in seven subjects (25 ± 1 years, mean ± S.E.M.) using the variable-pressure neck collar technique at rest and during one-legged knee extension exercise. The oral ingestion of glyburide (5 mg) did not change mean arterial pressure (MAP at rest (86 versus 89 mmHg, P > 0.05), but did appear to increase MAP during exercise (87 versus 92 mmHg, P = 0.053). However, the CBR-MAP function curves were similar at rest before and after glyburide ingestion. The CBR-mediated decrease in LVC observed at rest (∼39%) was attenuated during exercise in the exercising leg (∼15%, P < 0.05). Oral glyburide ingestion partially restored CBR-mediated vasoconstriction in the exercising leg (∼40% restoration, P < 0.05) compared to control exercise. These findings indicate that K ATP channel activity modulates sympathetic vasoconstriction in humans and may prove to be an important mechanism by which functional sympatholysis operates in humans during exercise.
AB - In the present investigation we examined the role of ATP-sensitive potassium (K ATP ) channel activity in modulating carotid baroreflex (CBR)-induced vasoconstriction in the vasculature of the leg. The CBR control of mean arterial pressure (MAP) and leg vascular conductance (LVC) was determined in seven subjects (25 ± 1 years, mean ± S.E.M.) using the variable-pressure neck collar technique at rest and during one-legged knee extension exercise. The oral ingestion of glyburide (5 mg) did not change mean arterial pressure (MAP at rest (86 versus 89 mmHg, P > 0.05), but did appear to increase MAP during exercise (87 versus 92 mmHg, P = 0.053). However, the CBR-MAP function curves were similar at rest before and after glyburide ingestion. The CBR-mediated decrease in LVC observed at rest (∼39%) was attenuated during exercise in the exercising leg (∼15%, P < 0.05). Oral glyburide ingestion partially restored CBR-mediated vasoconstriction in the exercising leg (∼40% restoration, P < 0.05) compared to control exercise. These findings indicate that K ATP channel activity modulates sympathetic vasoconstriction in humans and may prove to be an important mechanism by which functional sympatholysis operates in humans during exercise.
UR - http://www.scopus.com/inward/record.url?scp=9244231105&partnerID=8YFLogxK
U2 - 10.1113/jphysiol.2004.071993
DO - 10.1113/jphysiol.2004.071993
M3 - Article
C2 - 15345750
AN - SCOPUS:9244231105
VL - 561
SP - 273
EP - 282
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 1
ER -