Experimental uremic neuropathy. Part 1. Decreased nerve conduction velocity in rats.

Acute and chronic renal failure were induced in adult male albino rats by conventional surgical methods. The glomerular filtration rate of rats with chronic uremia was reduced to approximately 15% of normal. Despite this drastic degree of renal failure, the motor nerve conduction velocity (MCV) increased from 47.5 +/- 6.4 m/s, preoperatively, to 55.6 +/- 4.0 m/s after 4 weeks. In rats with acute uremia, MCV decreased from 51.4 +/- 3.0 m/s to 45.2 +/- 2.7 m/s after 48 h. The conduction velocity, measured in vitro of excised sciatic nerves was 55.2 +/- 4.4 m/s in acute uremia and 64.7 +/- 4.7 m/s in a control group. There was no difference in the refractory period between these groups. It is concluded that this decrease in the nerve conduction velocity was not caused by changes in the composition of the extracellular fluid but rather by changes in the nodal membrane function.