BENEFICIAL EFFECT OF AN ACTH(4-9) ANALOG ON EXPERIMENTALLY-INDUCED DIABETIC AUTONOMIC NEUROPATHY IN THE EYE OF THE RAT UNDER GENERAL-ANESTHESIA

While peripheral polyneuropathy is a well-known complication in diabet es mellitus, and the subject of a great deal of study, the clinical im portance of autonomic diabetic neuropathy is increasingly recognised. Using an animal model where the pupil diameter of the eye serves as a parameter of autonomic function, we produced an age and weight curve o f pupil diameter and studied the development of autonomic neuropathy i n rats with streptozotocin-induced diabetes. We show that diabetic rat s develop significantly (P < 0.009) smaller pupils compared with contr ols, most probably due to a defective sympathetic input, caused by sym pathetic neuropathy. Treatment with the neurotrophic peptide Org 2766, a synthetic ACTH(4-9) analogue, prevents the occurrence of this sympa thetic neuropathy, as the pupil diameters in the ACTH(4-9) analogue-tr eated group are significantly (P < 0.05) larger than the pupils of pla cebo-treated rats, and are comparable to the pupil diameters of the ra ts in the control group.