Insulin binding and glucose transport in adipocytes of acarbose-treated Zucker lean and obese rats

The intestinal glucosidase inhibitor acarbose was administered as a dietary admix (30 mg/100 g chow diet) to male Zucker obese and lean rats. After 15 weeks, epididymal fat pads were removed and adipocytes isolated by collagenase digestion. Equilibrium binding of A-14 tyrosine ¹²⁵I-insulin, and transport of U-¹⁴C-glucose was determined in adipocytes incubated for 50 min at 37°C in 0-16000 pM insulin. Insulin binding/cell was enhanced two-fold in lean (P < 0.01) and obese (n.s.) drug groups. In drug-treated leans, increased sensitivity of glucose transport to submaximally stimulating concentrations of insulin was observed (P < 0.02). For both genotypes, acarbose mildly decreased insulin levels and body weight gain, although adipocyte size was unaffected. Results indicate that enhanced insulin binding accompanies metabolic improvements induced by acarbose in lean Zucker rats.