Abstract
The objective of the present study was to elucidate the possible mechanism of uremic neuropathy using an experimental model. Bilateral nephrectomy was performed to induce acute renal failure in rats. Rats given sham operation were used as controls. Forty-eight hours after the operation, measurements were made of motor nerve conduction velocities, axoplasmic electrolyte concentration and cross-sectional area of myelinated fibers in the sciatic nerves. The axoplasmic Na, K and Cl concentrations were measured by electron X-ray microanalysis using freshly freeze-dried thin sections.
The results were as follows: 1) The sciatic motor nerve conduction velocity in uremic rats was significantly decreased compared with that in the controls (29.2±3.1m/sec. vs. 37.1±1.9m/sec., n=20, mean±S. D.; p<0.01). 2) Axoplasmic Na concentration in sciatic nerves from uremic rats was significantly decreased compared with that from the controls (6.0±0.7mmol/kg wet weight vs. 12.7±1.4mmol/kg wet weight, n=10, mean±S. D.; p<0.05). 3 An approximately 16% reduction in the cross-sectional area of myelinated fibers was observed in uremic rats.
These results suggest that impairment of Na permeability and atrophy of the myelinated fibers may play an important role in the decreased motor nerve conduction velocities in acute renal failure.
