Effects of diabetes on the morphine-induced Straub tail reaction in mice.

The effects of diabetes on the morphine-induced Straub tail reaction were examined in mice. The Straub tail reaction induced by s.c. administration of morphine was significantly less in diabetic mice than in non-diabetic mice. The morphine-induced Straub tail reaction was significantly reduced following pretreatment with beta-funaltrexamine, a selective mu-opioid receptor antagonist, in both diabetic and non-diabetic mice. Furthermore, the morphine-induced Straub tail reaction was also significantly reduced in both diabetic and non-diabetic mice following pretreatment with naloxonazine, a selective mu1-opioid receptor antagonist. These results suggest that mice with diabetes are hypo-responsive to mu1-opioid receptor-mediated Straub tail reaction.