Effect of acetylcholine stimulation on calcium and sodium uptake by the isolated rat pancreas.
1. The role of Ca2+ and Na+ ions in 'stimulus-secretion' coupling in the isolated uncinate pancreas of 4-week-old rats has been examined using radioisotope tracer techniques. The amount of 45Ca2+ and 22Na+ (mumole/g wet wt.) taken up by unstimulated glands was compared to that of glands in which amylase release was stimulated by ACh(10(-5) M) at various incubation times. 2. The amount of 45Ca taken up by the glands within 60 min of incubation was not found to be increased by the presence of ACh(10(-5) M). In fact, during short incubation periods the 45Ca uptake was significantly less in the stimulated glands than the unstimulated glands. 3. Presence of ACh(10(-5) M) did cause a significant initial increase in 22Na uptake lasting up to 20 min from onset of stimulation. 4. These results indicate that the rise in intracellular Ca2+ concentration which is suggested by an increase in 45Ca efflux during the action of pancreatic secretagogues, is not a consequence of increased 45Ca uptake by the pancreas; but they indicate that an initial action of ACh could be to elicit an increase in Na+ influx and that Na+ ions are likely to be involved in the action of ACh on pancreatic acinar cells.
D000109:Acetylcholine / Q000494:pharmacology*; D000681:Amylases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D012964:Sodium / Q000378:metabolism*; D013268:Stimulation, Chemical
D012964:Sodium; D000681:Amylases; D000109:Acetylcholine; D002118:Calcium