Adenosine in the immature kidney.

Intrarenal adenosine could be a physiological regulator of glomerular filtration rate and renal blood flow, acting on the renal arteriolar tone. Recent experimental evidence strongly suggests an important role for intrarenal adenosine in the hemodynamic renal changes observed in ischemic acute renal failure (ARF), as well as in various other experimental models of ARF. Adenosine also appears to play a key role in the hypoxemia-induced renal insufficiency in newborn animals. The deleterious functional changes induced by hypoxemia can be prevented by low-dose theophylline, a xanthine with strong adenosine antagonistic properties. The overall experimental data suggest that adenosine vasodilates the efferent glomerular arteriole and vasoconstricts the afferent arteriole when the renin-angiotensin system is stimulated.