Effect of chronic experimental diabetes on vascular smooth muscle function in dog femoral artery

To understand the effects of diabetes on vascular smooth muscle function and the underlying mechanisms involved, we examined the responses to noradrenaline (NA), serotonin, KCl and acetylcholine in the femoral artery of mongrel dogs with chronic diabetes (3 months)-induced subtotal pancreatectomy. Isolated ring segments of diabetic dog femoral artery exhibited an increased response to serotonin, a decreased response to NA, an unchanged response to KCl and a decreased endothelium-dependent relaxation to acetylcholine as compared with controls. The sensitivity (pD2) of diabetic femoral artery rings to NA and serotonin was markedly diminished. These results suggest that changed responsiveness of arteries from diabetic animals to NA, serotonin and acetylcholine could be the reflection of an alteration in the contractile machinery or the results of a decrease in endothelium-derived relaxing factor release in diabetic blood vessels.