Ca++ and pancreatic amylase release.
The effects of Ca'++ on release of amylase by mouse pancreas in vitri was studied. The cholinergic agonist bethanechol was depressed about 50% in O Ca'++ medium. When pancreatic fragments were superfused with O Ca'++ medium, bethanechol still produced a normal stimulation of amylase release after half of the total tissue Ca'++ was washed out.  This Ca'++ loss included both extracellular and some intracellularCa'++.  Uptake and equilibration of '45Ca'++ into pancreatic fragments was multiphasic, with total equilibration with stable Ca'++ still not reached after 3 h.  Addition of bethanechol had no effect on the rate of '45Ca uptake and equilibration.  '45Ca'++ efflux was not influenced by superfision in O Ca'++ medium, while thestimulation of '45Ca'++ efflux by bethanechol was enhanced.  It is concluded that extracellular Ca'++ and/or Ca'++ influx is not of major importance in triggering pancreatic enzyme release, but that extracellular Ca'++ may regulate the release process thus accounting for the parallel changes in unstimulated and stimulated amylase release.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D001464:Barium / Q000494:pharmacology; D001626:Bethanechol Compounds; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007444:Inulin / Q000378:metabolism; D008297:Male; D051379:Mice; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D013268:Stimulation, Chemical; D013324:Strontium / Q000494:pharmacology; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors
D001626:Bethanechol Compounds; D001464:Barium; D013395:Sucrose; D007444:Inulin; D000681:Amylases; D002118:Calcium; D013324:Strontium