A study of the renal responses in the rat to electrical stimulation of the afferent nerves of the brachial plexus.

Brachial nerve stimulation at 3 Hz in sodium pentobarbitone-anaesthetized rats, with constant renal arterial pressure, increased systemic blood pressure, did not alter glomerular filtration rate but reduced renal blood flow, absolute and fractional sodium excretions and urine flow. In renally denervated animals, stimulation caused similar changes in blood pressure and renal haemodynamics but significantly smaller reductions in sodium and water excretions. Brachial nerve stimulation at 30 Hz caused changes in blood pressure and renal function identical to those obtained with low-frequency stimulation but these responses were not modified by renal denervation. The results show that renal nerves are necessary to promote sodium and water reabsorption in response to low- but not high-frequency stimulation of the brachial nerves in the rat.