Role of renal nerves on renal functional change after back heating in the rat.

This study was designed to investigate the possible role of renal nerves in the regulation of renal function after the application of heat (BH), by means of an electric heating pad (42 +/- 1 degree C) to the skin of the back overlying the kidneys. Both renal efferent (RENA) and renal afferent nervous activity (RANA) were recorded in 7 anesthetized female Wistar rats. It was found that RENA reduced to less than 80% of the control level during 30 min of back heating, accompanied by an increase in excretion of urine, sodium and potassium, and enhanced the glomerular filtration rate. BH in 9 chronic bilateral renal denervated rats (RD) showed the same renal responses as in the renal nerve intact rats (RI) after back heating. It is concluded that renal nerves played only a partially role in the renal diuretic action of back heating.