Adenosine and Renal Function

Abstract

Exogenous adenosine has been shown to affect nearly all aspects of renal function: renal blood flow and its distribution within the kidney, glomerular filtration rate, renin secretion, urine flow, sodium excretion, transmitter release from renal efferent nerves, and the activity of renal afferent nerves. Many of these effects are produced by adenosine receptors, since the effects are antagonized by alkylxanthines and mimicked by adenosine analogs that act as adenosine receptor agonists. The orders of potency of agonists in producing some of these effects have been determined, and therefore the subclasses of adenosine receptors that are involved have been established. These observations, taken together with the observation that kidneys produce and release adenosine into extracellular fluids, suggest that variations in the concentration of endogenously released adenosine could play important roles in renal function and/or dysfunction. Indeed, it has been postulated that adenosine is the mediator of several physiological and pathophysiological phenomena: the autoregulation of renal blood flow and glomerular filtration rate, the tubuloglomerular feedback response, the effect of macula densa cells on the adjacent reninsecreting juxtaglomerular cells, the hemodynamic changes in acute renal failure, and hypertension in some experimental animal models.