NEURAL CONTROL OF RENAL-FUNCTION

The renal nerves are the communication link between the central nervou s system and the kidney. In response to multiple peripheral and centra l inputs, efferent renal sympathetic nerve activity is altered so as t o convey information to the major structural and functional components of the kidney, the vessels, glomeruli, and tubules, each of which is innervated. At the level of each of these individual components, infor mation transfer occurs via interaction of the neurotransmitter release d at the sympathetic nerve terminal-neuroeffector junction with specif ic postjunctional receptors coupled to defined intracellular signaling and effector systems. In response to normal physiological stimuli, ch anges in efferent renal sympathetic nerve activity contribute importan tly to homeostatic regulation of renal blood flow, glomerular filtrati on rate, renal tubular epithelial cell solute and water transport, and hormonal release. Afferent input from sensory receptors located in th e kidney participates in this reflex control system via renorenal refl exes that enable total renal function to be self-regulated and balance d between the two kidneys. In pathophysiological conditions, abnormal regulation of efferent renal sympathetic nerve activity contributes si gnificantly to the associated abnormalities of renal function which, i n turn, are of importance in the pathogenesis of the disease.