Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice

CP Coomans, NR Biermasz, JJ Geerling, B Guigas… - Diabetes, 2011 - Am Diabetes Assoc
CP Coomans, NR Biermasz, JJ Geerling, B Guigas, PCN Rensen, LM Havekes, JA Romijn
Diabetes, 2011Am Diabetes Assoc
OBJECTIVE Insulin inhibits endogenous glucose production (EGP) and stimulates glucose
uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory
effects of insulin on EGP. We examined the contribution of central insulin signaling on
circulating insulin–stimulated tissue-specific glucose uptake. RESEARCH DESIGN AND
METHODS Tolbutamide, an inhibitor of ATP-sensitive K+ channels (KATP channels), or
vehicle was infused into the lateral ventricle in the basal state and during hyperinsulinemic …
OBJECTIVE
Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin–stimulated tissue-specific glucose uptake.
RESEARCH DESIGN AND METHODS
Tolbutamide, an inhibitor of ATP-sensitive K+ channels (KATP channels), or vehicle was infused into the lateral ventricle in the basal state and during hyperinsulinemic-euglycemic conditions in postabsorptive, chow-fed C57Bl/6J mice and in postabsorptive C57Bl/6J mice with diet-induced obesity. Whole-body glucose uptake was measured by d-[14C]glucose kinetics and tissue-specific glucose uptake by 2-deoxy-d-[3H]glucose uptake.
RESULTS
During clamp conditions, intracerebroventricular administration of tolbutamide impaired the ability of insulin to inhibit EGP by ∼20%. In addition, intracerebroventricular tolbutamide diminished insulin-stimulated glucose uptake in muscle (by ∼59%) but not in heart or adipose tissue. In contrast, in insulin-resistant mice with diet-induced obesity, intracerebroventricular tolbutamide did not alter the effects of insulin during clamp conditions on EGP or glucose uptake by muscle.
CONCLUSIONS
Insulin stimulates glucose uptake in muscle in part through effects via KATP channels in the central nervous system, in analogy with the inhibitory effects of insulin on EGP. High-fat diet–induced obesity abolished the central effects of insulin on liver and muscle. These observations stress the role of central insulin resistance in the pathophysiology of diet-induced insulin resistance.
Am Diabetes Assoc