AJP - Endocrinology and Metabolism, Vol 264, Issue 2 E161-E166, Copyright © 1993 by American Physiological Society
Nerve function in experimental diabetes in rats: effects of electrical stimulation
N. E. Cameron, M. A. Cotter, S. Robertson and E. K. Maxfield
Department of Biomedical Sciences, University of Aberdeen, Scotland, United Kingdom.
The effects of unilateral electrical stimulation of the peroneal sciatic
nerve branch were studied in streptozocin-diabetic rats of 12-wk duration.
Stimulation was carried out over 7 days (10 Hz, 8 h/day) with chronically
implanted electrodes. Compared with controls, there was a 25% conduction
velocity (CV) deficit for the peroneal nerve supplying tibialis anterior
muscle in the unstimulated leg, which was corrected by stimulation. For
tibial fibers supplying soleus muscle, a similar diabetic CV deficit (20%)
was normalized by stimulation, although soleus axons were not directly
activated. In saphenous nerve, which has a functionally separate vascular
supply, peroneal stimulation was ineffective. In anesthetized diabetic
rats, stimulation caused an 18% reduction in tibialis anterior CV after 4
h. However, serial measurements showed progressive normalization of CV over
4 days of stimulation. On termination, CV returned to diabetic levels over
36-60 h. Sciatic nerve showed a 70% increase in resistance to hypoxic
conduction failure with diabetes, which was halved by chronic stimulation.
Acute experiments demonstrated that peroneal stimulation increased sciatic
vascular conductance by 60%. We conclude that stimulation causes
activity-related improvements in diabetic nerve blood flow and metabolism.
