Diabetes-induced alterations of autonomic nerve function in the cat

The susceptibility to competitive ganglionic blocking agents such as hexamethonium (C6), tetraethylammonium bromide (TEAB), mecamylamine and d-tubocurarine (d-TC), of the superior cervical ganglion in cats with pancreatectomy and spontaneous diabetes or in animals treated with contrainsular drugs such as cortisone or dihydrochlorothiazide, was found to be decreased as compared to the reactivity of normal controls. The increased tolerance to ganglioplegics was not correlated with the elevation of the blood sugar level, and proved to be resistant to an acute administration of insulin. The results could not be explained by a decrease in the specific cholinesterase activity of the ganglionic tissue due to diabetes. Alteration of the peripheral autonomic synaptic transmission may be an early sign of diabetic neuropathy.