Effects of Three Purine‐related Compounds on Pancreatic Exocrine Secretion in the Dog

Abstract

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.

Acetylcholine, ATP, Bombesin, and Cholecystokinin Stimulate 125I Efflux from a Human Pancreatic Adenocarcinoma Cell Line (BxPC-3)

“…Figure 3 shows that ionomycin (0.5 (17). We therefore tested the effects of ATP, ADP, and AMP on 1251 efflux from BxPC-3 cells.…”

“…We used an 1251 efflux assay to monitor the anion permeability of BxPC-3 cells. For the efflux experiments, BxPC-3 cells (passages [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] were seeded at a density of lo6 celldm1 onto 52-mm plastic culture dishes and grown for a period of 8 days, by which time they had reached confluency.…”

Purinergic signalling in the pancreas in health and disease

“…This finding supports nicely earlier studies performed on dog whole pancreas. Although adenosine decreased blood flow, it enhanced secretinstimulated HCO K 3 and fluid secretion (Yamagishi et al 1985(Yamagishi et al , 1986. A pharmacological study indicated that it was the A 2A adenosine receptor that was involved in this secretory response in dog pancreas (Iwatsuki 2000).…”

Adenosine receptors in rat and human pancreatic ducts stimulate chloride transport

“…Indeed, adenosine response was not found on isolated rat acini. In intact dog pancreas, adenosine modulated secretion evoked by secretin [39,40]. Using agonists and antagonists for adenosine receptors, it was implicated that A 2A receptors were involved in HCO À 3 secretory response [16].…”