Delta opioid receptors mediate glucose uptake in skeletal muscles of lean and obese-diabetic (ob/ob) mice

Specific binding sites for [I-125]beta -endorphin and the partial derivativ e (1)-opioid [H-3][D-pen(2), D-pen(5)]enkephalin (DPDPE) were quantified us ing autoradiography in soleus and extensor digitorum longus (EDL) muscles o f lean and obese-diabetic (ob/ob) mice. The density of binding was signific antly higher in obese-diabetic than lean mice. The uptake of 2-deoxy-D-[1-H -3]deoxyglucose, a nonmetabolized glucose analogue, into isolated soleus an d EDL muscles was stimulated by beta -endorphin, beta -endorphin 1-27, and DPDPE, but not by the partial derivative (2)-opioid deltorphin II. Both bet a -endorphin and DPDPE stimulated deoxyglucose uptake in obese-diabetic mic e. Thus, glucose transport in skeletal muscle may be partly mediated via pa rtial derivative (1)-opioid receptors. The increased receptor density in ob ese-diabetic mice may be an adaptive response. Copyright (C) 2001 by W.B. S aunders Company.