Effect of chronic morphine administration on glucose tolerance and insulin binding to isolated rat adipocytes

Morphine addiction was induced in six male Wistar rats. Improved glucose tolerance (peak value less by 28%, p<0.01) was observed in chronically morphinized rats as compared to the control rats, injected with saline. An increase in the maximal specific binding of 125I-labeled insulin to unit membrane area of adipocytes was observed in the experimental group (p < 0.01). The changes in insulin receptor number could be responsible for the improved glucose tolerance observed during morphine addiction.