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AICAR administration causes an apparent enhancement of muscle and liver insulin action in insulin-resistant high-fat-fed rats

journal contribution
posted on 2023-05-17, 13:49 authored by Miguel IglesiasMiguel Iglesias, Ye, JM, Frangioudakis, G, Saha, AK, Tomas, E, Ruderman, NB, Cooney, J, Kraegen, EW
Exercise improves insulin sensitivity. As AMP-activated protein kinase (AMPK) plays an important role in muscle metabolism during exercise, we investigated the effects of the AMPK activator 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) on insulin action in insulin-resistant high-fat-fed (HF) rats. Rats received a subcutaneous injection of 250 mg/kg AICAR (HF-AIC) or saline (HF-Con). The next day, euglycemic-hyperinsulinemic clamp studies were performed. Glucose infusion rate during the clamp was enhanced (50%) in HF-AIC compared with HF-Con rats. Insulin-stimulated glucose uptake was improved in white but not in red quadriceps, whereas glycogen synthesis was improved in both red and white quadriceps of HF-AIC rats. HF-AIC rats also showed increased insulin suppressibility of hepatic glucose output (HGO). AICAR-induced responses in both liver and muscle were accompanied by reduced malonyl-CoA content. Clamp HGO correlated closely with hepatic triglyceride content (r = 0.67, P < 0.01). Thus, a single dose of AICAR leads to an apparent enhancement in whole-body, muscle, and liver insulin action in HF rats that extends beyond the expected time of AMPK activation. Whether altered tissue lipid metabolism mediates AICAR effects on insulin action remains to be determined. Follow-up studies suggest that at least some of the post-AICAR insulin-enhancing effects also occur in normal rats. Independent of this, the results suggest that pharmacological activation of AMPK may have potential in treating insulin-resistant states and type 2 diabetes.

History

Publication title

Diabetes

Volume

51

Pagination

2886-2894

ISSN

0012-1797

Department/School

School of Health Sciences

Publisher

Amer Diabetes Assoc

Place of publication

1701 N Beauregard St, Alexandria, USA, Va, 22311-1717

Rights statement

Copyright 2002 American Diabetes Association.

Repository Status

  • Restricted

Socio-economic Objectives

Clinical health not elsewhere classified

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