Drug Restores Heart Insulin Sensitivity in Obese Mice
Captopril has no effect on insulin levels or glucose tolerance
THURSDAY, July 24 (HealthDay News) -- Treating obese mice with Captopril, an inhibitor of the renin-angiotensin system, restores insulin sensitivity in their hearts but does not affect insulin levels or glucose tolerance, researchers report in the August issue of Endocrinology.
Imene Tabbi-Anneni, Ph.D., and colleagues from the University of Utah School of Medicine in Salt Lake City treated genetically obese mice with 4 mg/kg/day of Captopril for four weeks.
The researchers found that the Captopril-treated mice still had high insulin levels and impaired glucose tolerance. However, Captopril restored the ability of insulin to regulate fatty acid oxidation and glycolysis in their hearts, with higher rates of fatty acid oxidation and lower levels of glycolysis. Captopril also normalized the phosphorylation of AMP-activated protein kinase (AMPK), which suggested an improvement in myocardial energetics, according to the authors.
"Angiotensin-converting enzyme inhibitors restore the responsiveness of [genetically obese] mouse hearts to insulin and normalizes AMPK activity independently of effects on systemic metabolic homeostasis," Tabbi-Anneni and colleagues conclude.