Endogenous adenosine restrains renin release during sodium restriction.

The purpose of this study was to determine the role of endogenous adenosine in controlling renin release during both a normal and low sodium diet. To probe the involvement of endogenous adenosine in the control of renin release, we examined the effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl)xanthine (DPSPX), on renin release in rats fed either a normal or low sodium diet. All studies were conducted in the in situ autoperfused kidney. DPSPX significantly increased arterial and renal venous levels of renin in both groups of animals; however, statistical analysis of the data (2-factor analysis of variance) indicated that DPSPX increased aortic and renal venous levels of renin more in rats fed a low sodium diet compared to rats fed a normal sodium diet. Also, whereas DPSPX did not significantly increase the venoarterial difference of renin activity across the kidney or the calculated net secretion rate of renin in rats on a normal sodium diet, both of these indices of renin release were significantly increased by DPSPX in rats on a low sodium diet. The effects of DPSPX on renin release could not be explained by changes in renal hemodynamics or excretory function. Additional experiments with rats on a low sodium diet that were treated with propranolol demonstrated that the effects of DPSPX on renin release were independent of the sympathetic nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)