Antiobesity effect of diazoxide in obese Zucker rats

Metabolism. 1996 Mar;45(3):334-41. doi: 10.1016/s0026-0495(96)90287-5.


Hyperinsulinism and insulin resistance are characteristic findings in obese subjects. Obesity in both humans and experimental animals is associated with a reduced number of insulin receptors and a decreased insulin-mediated glucose disposal, whereas sensitivity to insulin's antilipolytic action is unaltered. To evaluate the antiobesity effect of diazoxide (DZ), an inhibitor of glucose-stimulated insulin release, 7-week-old Zucker obese and lean rats were studied. Obese and lean rats were grouped into DZ-treated (150 mg/kg/d) and control (C) groups. DZ-treated obese rats consumed similar amounts of calories per kilogram body weight (BW) compared with C obese animals, but gained less weight (P<.01). Postabsorptive plasma free fatty acids (FFA), cholesterol, and triglycerides were significantly higher in obese versus lean animals (P<.01). DZ treatment reduced plasma triglyceride levels in obese animals (P<.001), but had no significant effect on FFA or cholesterol concentrations. Plasma glucose concentrations in the postabsorptive state and during glucose tolerance tests (GTTs) were significantly lower in DZ obese versus C obese rats (P<.01) despite a decrease in plasma insulin concentrations in DZ-treated animals (P<.01). In contrast, DZ lean rats developed glucose intolerance (P<.05). Sensitivity and responsiveness to the antilipolytic effect of insulin in isolated adipocytes were significantly decreased in DZ obese as compared with C obese rats (P<.01). Moreover, adipocyte specific insulin receptor binding was increased in both DZ lean and DZ obese animals (P<.01). This was accompanied by increased basal and insulin-stimulated glucose transport in both genotypes (P<.01). In conclusion, DZ increased insulin receptor binding and glucose transport while decreasing hyperinsulinemia and insulin sensitivity to the antilipolytic action of insulin. This combined effect resulted in improved glucose tolerance and a decrease in weight gain in obese rats, implying that pharmacologic modification of the disturbed insulin metabolism of obesity may be therapeutically beneficial.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / drug effects
  • Animals
  • Blood Glucose / analysis
  • Diazoxide / therapeutic use*
  • Energy Intake
  • Female
  • Glucose / metabolism
  • Insulin / metabolism*
  • Insulin / pharmacology
  • Lipids / blood
  • Lipolysis / drug effects
  • Obesity / drug therapy*
  • Obesity / metabolism
  • Rats
  • Rats, Zucker
  • Receptor, Insulin / analysis


  • Blood Glucose
  • Insulin
  • Lipids
  • Receptor, Insulin
  • Glucose
  • Diazoxide