Muscle metabolism and control of capillary blood flow: insulin and exercise.
The evidence that muscle metabolism is determined by available capillary surface area is examined. From newly developed methods it is clear that exercise and insulin mediate capillary recruitment as part of their actions in vivo. In all insulin-resistant states examined thus far, insulin-mediated capillary recruitment is impaired with little or no change to the exercise response. Control mechanisms for capillary recruitment for exercise and insulin are considered, and the failure of the microvasculature to respond to insulin is examined for possible mechanisms that might account for impaired vascular responses to insulin in insulin resistance.
Rattigan
Stephen
S
University of Tasmania, Biochemistry, School of Medicine, Hobart, Tasmania, Australia. s.rattigan@utas.edu.au
Bradley
Eloise A
EA
Richards
Stephen M
SM
Clark
Michael G
MG
D000818:Animals; D002196:Capillaries / Q000502:physiology; D016207:Cytokines / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology; D007328:Insulin / Q000502:physiology*; D007333:Insulin Resistance; D024821:Metabolic Syndrome / Q000503:physiopathology; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism*; D005082:Physical Exertion / Q000502:physiology; D012039:Regional Blood Flow
D016207:Cytokines; D007328:Insulin