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Hemodynamic actions of insulin in rat skeletal muscle: evidence of capillary recruitment


Rattigan, S and Clark, MG and Barrett, EJ, Hemodynamic actions of insulin in rat skeletal muscle: evidence of capillary recruitment, Diabetes, 46, (9) pp. 1381-1388. ISSN 0012-1797 (1997) [Refereed Article]

DOI: doi:10.2337/diabetes.46.9.1381


Insulin-induced increases in blood flow are hypothesized to enhance overall glucose uptake by skeletal muscle. Whether the insulin-mediated changes in blood flow are associated with altered blood flow distribution and increased capillary recruitment in skeletal muscle is not known. In the present study, the effects of insulin on hemodynamic parameters in rat skeletal muscle in vivo were investigated. Mean arterial blood pressure, heart rate, femoral blood flow, hind leg vascular resistance, and glucose uptake were measured in control and euglycemic insulin-clamped (10 mU · min-1 · kg-1) anesthetized rats. Blood flow distribution within the hind leg muscles was assessed by measuring the metabolism of 1-methylxanthine (1- MX), an exogenously added substrate for capillary xanthine oxidase. Insulin treatment had no effect on heart rate but significantly increased arterial blood pressure (12 mmHg) and femoral blood flow (80%) and decreased hind leg vascular resistance (31%). Changes were similar in magnitude and in time of onset to those reported in humans. Insulin treatment increased hind leg glucose uptake approximately fourfold and also increased hind leg 1-MX metabolism by 50%, suggesting increased exposure to endothelial xanthine oxidase. To ascertain whether the increased 1-MX metabolism was simply due to increased bulk femoral blood flow, epinephrine was infused at a dose (0.125 μg · min-1 · kg-1) chosen to match the insulin-induced increase in femoral blood flow. This dose of epinephrine had no significant effects on arterial blood pressure or heart rate but increased femoral blood flow and lowered hind leg vascular resistance to a similar extent as insulin. Epinephrine did not significantly alter 1-MX metabolism as compared with control animals. These results demonstrate that insulin increases total hind leg blood flow and metabolism of 1-MX, suggesting a recruitment of capillary blood flow in rat hind leg not mimicked by epinephrine.

Item Details

Item Type:Refereed Article
Research Division:Biomedical and Clinical Sciences
Research Group:Medical physiology
Research Field:Systems physiology
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Rattigan, S (Professor Stephen Rattigan)
UTAS Author:Clark, MG (Professor Michael Clark)
ID Code:11326
Year Published:1997
Web of Science® Times Cited:214
Deposited By:Biochemistry
Deposited On:1997-08-01
Last Modified:2011-08-12

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