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Blood flow and muscle metabolism: a focus on insulin action

journal contribution
posted on 2003-02-01, 00:00 authored by M G Clark, M G Wallis, E J Barrett, Michelle KeskeMichelle Keske, S M Richards, L H Clerk, S Rattigan
The vascular system controls the delivery of nutrients and hormones to muscle, and a number of hormones may act to regulate muscle metabolism and contractile performance by modulating blood flow to and within muscle. This review examines evidence that insulin has major hemodynamic effects to influence muscle metabolism. Whole body, isolated hindlimb perfusion studies and experiments with cell cultures suggest that the hemodynamic effects of insulin emanate from the vasculature itself and involve nitric oxide-dependent vasodilation at large and small vessels with the purpose of increasing access for insulin and nutrients to the interstitium and muscle cells. Recently developed techniques for detecting changes in microvascular flow, specifically capillary recruitment in muscle, indicate this to be a key site for early insulin action at physiological levels in rats and humans. In the absence of increases in bulk flow to muscle, insulin may act to switch flow from nonnutritive to the nutritive route. In addition, there is accumulating evidence to suggest that insulin resistance of muscle in vivo in terms of impaired glucose uptake could be partly due to impaired insulin-mediated capillary recruitment. Exercise training improves insulin-mediated capillary recruitment and glucose uptake by muscle.

History

Journal

American journal of physiology: endocrinology and metabolism

Volume

284

Issue

2

Pagination

E241 - E258

Publisher

American Physiological Society

Location

Bethesda, Md.

ISSN

0193-1849

Language

eng

Publication classification

CN.1 Other journal article

Copyright notice

2003, American Physiological Society