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Microvascular recruitment is an early insulin effect that regulates skeletal muscle glucose uptake in vivo
journal contribution
posted on 2023-05-16, 15:28 authored by Michelle Keske, Clerk, LH, Lindner, JR, Klibanov, AL, Michael ClarkMichael Clark, Stephen RattiganStephen Rattigan, Barrett, EJInsulin increases glucose disposal into muscle. In addition, in vivo insulin elicits distinct nitric oxide synthase-dependent vascular responses to increase total skeletal muscle blood flow and to recruit muscle capillaries (by relaxing resistance and terminal arterioles, respectively). In the current study, we compared the temporal sequence of vascular and metabolic responses to a 30-min physiological infusion of insulin (3 mU · min-1 · kg-1, euglycemic clamp) or saline in rat skeletal muscle in vivo. We used contrast-enhanced ultrasound to continuously quantify microvascular volume. Insulin recruited microvasculature within 5-10 min (P < 0.05), and this preceded both activation of insulin-signaling pathways and increases in glucose disposal in muscle, as well as changes in total leg blood flow. Moreover, L-NAME (Nω-nitro-L-arginine-methyl ester), a specific inhibitor of nitric oxide synthase, blocked this early microvascular recruitment (P < 0.05) and at least partially inhibited early increases in muscle glucose uptake (P < 0.05). We conclude that insulin rapidly recruits skeletal muscle capillaries in vivo by a nitric oxide-dependent action, and the increase in capillary recruitment may contribute to the subsequent glucose uptake.
History
Publication title
DiabetesVolume
53Issue
6Pagination
1418-1423ISSN
0012-1797Department/School
Menzies Institute for Medical ResearchPublisher
American Diabetes AssociationPlace of publication
Alexandria, USARepository Status
- Restricted