Renal nerves in compensatory renal response to contralateral renal denervation

Abstract

Acute unilateral renal denervation and the resultant diuresis and natriuresis are accompanied by a compensatory antidiuresis and antinatriuresis from the opposite kidney. The renal sympathetic nerves may mediate this adaptive response. In the volume-expanded rat, acute left renal denervation increased left kidney fractional Na excretion from 4.4 .+-. 0.6 to 5.9 .+-. 0.6%, while right kidney fractional Na excretion decreased from 4.3 .+-. 0.6 to 3.5 .+-. 0.5%. Subsequent acute right renal denervation increased right kidney fractional Na excretion from 3.5 .+-. 0.5 to 4.7 .+-. 0.6%. Measurement of efferent left renal sympathetic nerve activity before and after acute right renal denervation showed an increase from 10.9 .+-. 0.8 to 16.0 .+-. 1.4 Hz. When both kidneys were simultaneously subjected to acute renal denervation, fractional excretion of Na increased bilaterally. In uninephrectomized rats subjected to acute denervation of the remaining kidney, fractional excretion of Na increased. Glomerular filtration rate was unchanged throughout in all studies. The compensatory renal response to acute contralateral renal denervation is mediated by the efferent renal sympathetic nerves.