Stimulation of adenylate cyclase activity via A2-adenosine receptors in isolated tubules of the rabbit renal cortex.
Adenylate cyclase activity in a tubular fraction obtained from rabbit renal cortex was stimulated by typical adenosine receptor agonists with a rank order of potency NECA (5'-(N-ethyl-carboxamido)-adenosine) (EC50 = 0.48 mumol/l) greater than R-PIA [(-)N6 (R-phenylisopropyl)-adenosine] (3.22 mumol/l). The stimulatory effect of NECA was competitively antagonized by 8-phenyltheophylline. Contamination of the tubular fraction with glomeruli and microvessels was less than 2%, as verified by tissue renin determination and could, therefore, be ruled out as being responsible for the observed effect. Tubular A2-adenosine receptors are probably involved in the control of renal electrolyte secretion and may represent the site of action of methylxanthines.
Freissmuth
M
M
Nanoff
C
C
Tuisl
E
E
Schuetz
W
W
D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000201:enzymology*; D007684:Kidney Tubules / Q000201:enzymology*; D011817:Rabbits; D011863:Radioimmunoassay; D011983:Receptors, Purinergic / Q000378:metabolism*; D012083:Renin / Q000378:metabolism; D013329:Structure-Activity Relationship
D011983:Receptors, Purinergic; D012083:Renin; D000262:Adenylyl Cyclases; D000241:Adenosine