Effect of adenosine and adenosine analogs on [14C]aminopyrine accumulation by rabbit parietal cells.
Adenosine receptors that modulate adenylate cyclase activity have been identified recently in a number of tissues. Adenosine A2 receptor is stimulatory to adenylate cyclase, whereas adenosine A1 receptor is inhibitory to adenylate cyclase. We investigated the effect of adenosine and its analogs on [14C]aminopyrine accumulation by rabbit parietal cells. Rabbit gastric mucosal cells were isolated by enzyme digestion. Parietal cells were enriched by nonlinear percoll gradients. [14C]Aminopyrine accumulation was used as an indicator of acid secretion. The effect of 2-chloroadenosine on histamine-stimulated [14C]aminopyrine accumulation was studied. The effects of N-ethylcarboxamideadenosine, 2-chloroadenosine, stable analogs of adenosine, and adenosine on [14C]aminopyrine accumulation were assessed. Cyclic AMP content of parietal cells was determined by radioimmunoassay. Histamine and carbachol, known secretagogues, stimulated [14C]aminopyrine accumulation. 2-Chloroadenosine did not suppress histamine-stimulated [14C]aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine dose dependently increased [14C]aminopyrine accumulation. The order of potency was N-ethylcarboxamideadenosine greater than 2-chloroadenosine greater than adenosine. 8-Phenyltheophylline and theophylline, adenosine-receptor antagonists, or cimetidine did not have significant effects on the increase of AP uptake induced by 2-chloroadenosine. Coadministration of dipyridamole, and adenosine uptake inhibitor, augmented the effect of adenosine on [14C]aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine each induced a significant increase in cellular cyclic AMP. We conclude that there may be adenosine A2 receptors on rabbit parietal cells which modulate gastric acid secretion.
Ota
S
S
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Hiraishi
H
H
Terano
A
A
Mutoh
H
H
Kurachi
Y
Y
Shimada
T
T
Ivey
K J
KJ
Sugimoto
T
T
D015762:2-Chloroadenosine / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology*; D019830:Adenosine-5'-(N-ethylcarboxamide); D000632:Aminopyrine / Q000493:pharmacokinetics*; D000818:Animals; D002250:Carbon Radioisotopes; D000242:Cyclic AMP / Q000378:metabolism; D005744:Gastric Acid / Q000378:metabolism; D008297:Male; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D011817:Rabbits; D011983:Receptors, Purinergic / Q000302:isolation & purification* / Q000502:physiology
D002250:Carbon Radioisotopes; D011983:Receptors, Purinergic; D000632:Aminopyrine; D015762:2-Chloroadenosine; D019830:Adenosine-5'-(N-ethylcarboxamide); D000242:Cyclic AMP; D000241:Adenosine