Effect of decreased renal sympathetic nerve activity on renal tubular sodium reabsorption

The effect of decreases in renal sympathetic nerve activity on renal tubular sodium reabsorption was examined in anesthetized dogs. Reflex decreases in renal sympathetic nerve activity were produced by left atrial distention and stellate ganglion stimulation. Both interventions produced significant decreases in directly recorded efferent renal sympathetic nerve activity of 42 and 36%, respectively. With renal perfusion pressure held constant, neither glomerular filtration rate nor renal blood flow were significantly altered, but significant and reversible increases in urine flow and sodium excretion occurred. These studies demonstrate that reflex decreases in efferent renal sympathetic nerve activity result in decreases in renal tubular sodium reabsorption without changes in renal hemodynamics.