Introduction of calcium chelators into isolated rat pancreatic acini inhibits amylase release in response to carbamylcholine.
The Ca2+ chelators, EGTA and BAPTA, have been introduced into intact, isolated rat pancreatic acini using a hypotonic swelling method. This resulted in complete inhibition of amylase release, stimulated by carbamylcholine at a submaximal concentration and 82 - 85% inhibition at maximal concentrations. Acini swollen in the absence of Ca2+ chelators showed similar secretory responses to those of unswollen acini. Treatment of unswollen acini with chelators inhibited the maximum response to carbamylcholine by only 23%. The inhibitory effect of intracellular chelators was not due to ATP depletion or a lowering of the total cell Ca2+ content. Thus, these results provide the first direct demonstration that an increase in intracellular Ca2+ concentration is necessary for the stimulation of enzyme release from pancreatic acinar cells.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D005026:Ethylene Glycols / Q000494:pharmacology*; D007202:Indicators and Reagents / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
D005026:Ethylene Glycols; D007202:Indicators and Reagents; D004533:Egtazic Acid; D002217:Carbachol; D000681:Amylases; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid