The correlation between sensory nerve conduction velocities and three metabolic indices in rats treated with streptozotocin.

The fastest conduction velocities of the myelinated (A) and unmyelinated (C) sensory nerve fibres were measured in the saphenous nerves of rats made diabetic up to 5 weeks previously by injection of streptozotocin. The conduction velocity of the fastest A-alpha fibres in treated rats fell by 25% compared to control rats. The effect on the slow A-delta fibres was small but C-fibres were not affected. Levels of glycosylated haemoglobin, random plasma glucose, and the net changes in body weights were also measured. There were significant changes in these three metabolic indices among diabetic rats (p less than 0.001) and the three indices were inter-related. There was a good correlation between A-fibre conduction velocity and levels of glycosylated haemoglobin but no significant relationship between C-fibre conduction velocity and this metabolic index. A-fibre conduction velocity was statistically more correlated with levels of glycosylated haemoglobin than the other two metabolic indices (p less than 0.01).