Effects of three purine-related compounds on pancreatic exocrine secretion in the dog.
The effects of adenosine, adenosine 5'-triphosphate (ATP) and inosine on pancreatic exocrine secretion were investigated in the vascularly isolated and self-haemoperfused dog pancreas. Drugs were injected close-arterially (i.a.) in a single bolus. These three purine-related compounds per se did not affect resting rate of pancreatic secretion and the concentrations of protein and bicarbonate in the resting juice. Graded doses of adenosine (0.1-1.0 mg, i.a.) and ATP (0.1-1.0 mg i.a.) administered 1 min prior to secretin (0.025 clinical units, i.a.) increased a secretin-stimulated secretory volume dose-dependently, and the effects of adenosine and ATP were reversed by pretreatments with theophylline (0.3 mg, i.a.). Inosine (1.0 mg, i.a.) affected neither secretin- nor dopamine-stimulated (3 micrograms, i.a.) pancreatic secretion. Adenosine and ATP did not affect dopamine-stimulated pancreatic secretion. These results suggest that adenosine and ATP (or terminal phosphate hydrolyzed derivatives) enhance secretin-stimulated pancreatic exocrine secretion through 'P1' purine receptors in the exocrine cells, without conversion to inosine.
D000241:Adenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004298:Dopamine / Q000494:pharmacology; D005260:Female; D007288:Inosine / Q000494:pharmacology*; D008297:Male; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D012633:Secretin / Q000494:pharmacology
D012633:Secretin; D007288:Inosine; D000255:Adenosine Triphosphate; D000241:Adenosine; D004298:Dopamine