Effects of adenosine on renin release from isolated rat glomeruli and kidney slices.
Adenosine produced by the macula densa cells in response to changes in the tubular NaCl-concentration has been suggested to inhibit renin release in vivo. In order to test this suggestion we studied: incubated kidney cortical slices (KS) which contain both the macula densa and the entire afferent arteriole; superfused single microdissected glomeruli (LAG) without macula densa but with the afferent arteriole preserved; and superfused batches of selected glomeruli (SAG) containing only the juxtaglomerular cells closest to the glomerulus. For superfusion and incubation a bicarbonate Ringer solution was used. The specificity of the renin release process was validated by measuring adenylate kinase as a marker for cytoplasmatic leak. Adenosine (10 micrograms/ml) halved basal renin release from incubated KS as compared to controls (P less than 0.001, n = 8, 8). Renin release from LAG stimulated by calcium depletion was also inhibited (P less than 0.05, n = 8, 9) whereas basal release was not affected (n = 6, 12). No effect was detected neither on basal nor on calcium stimulated renin release from SAG. We conclude that adenosine inhibits renin release in vitro by a mechanism independent of a functioning nephron, and which involves only the JG-cells located in the afferent arteriole at some distance from the glomerulus.
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000033:anatomy & histology; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000378:metabolism*
D012083:Renin; D000241:Adenosine