Effects of voglibose (an α-glucosidase inhibitor) and pioglitazone (an insulin sensitizer)
on glycemic control and on the function of pancreatic islets were evaluated using
Goto-Kakizaki (GK) rats with non-insulin-dependent diabetes mellitus (NIDDM). Five
week administration (8-13 weeks of age in GK rats) of voglibose alone (added to the
chow at a concentration of 10 ppm), pioglitazone alone (10 mg/kg daily p.o.), or both
of the agents together significantly improved fasting plasma glucose levels and those
at 120 min in oral glucose tolerance tests. Insulin secretory capacity in response
to glucose of the isolated islets, assessed by batch incubation, was significantly
improved in the voglibose and in the voglibose plus pioglitazone groups. Eight-week
administration (5-13 weeks of age) of voglibose and voglibose plus pioglitazone successfully
lowered the fasting levels of plasma glucose and triglyceride. The glucose-responsiveness
in insulin release from the islets was also significantly recovered by the therapy.
The treatment increased the insulin content of the islets to almost twice that in
untreated controls. Thus, treatment by these drugs can not only effectively ameliorate
the metabolic derangement of NIDDM in GK rats, but it can also restore the deteriorated
islet function, possibly through protection from glucose toxicity.
Key words
Insulin Secretion - Insulin Resistance - α-Glucosidase Inhibitor - GK Rats - Glucose
Toxicity
