Effects of extracellular calcium and magnesium on bile-salt-stimulated amylase release from rat pancreatic acini.
The effects of extracellular calcium and magnesium on bile-salt-induced amylase release from rat pancreatic acini have been studied. The amylase releases caused by from 0.25 mM to 1.0 mM taurodeoxycholate (TDC) and by taurochenodeoxycholate (TCDC) at a concentration of more than 0.75 mM were reduced by ethylenediaminetetraacetic acid (EDTA) and increased by verapamil. EDTA and verapamil had no significant effect on the taurocholate (TC) (1.0-5.0 mM)-stimulated amylase release. The inhibiting effect of EDTA began to appear already during the initial 5 min and was not parallel to any change of lactate dehydrogenase release. The TDC- and TCDC-stimulated amylase release was strongly dependent on the concentrations of extracellular calcium and was only weakly dependent on extracellular magnesium. The TC-induced amylase release was slightly increased only at high concentrations of calcium and magnesium. It is suggested that the mechanism of dihydroxy bile-salt-induced amylase release from rat pancreatic acini is different from that of trihydroxy bile salt. The dihydroxy bile-salt-stimulated amylase release is dependent on extracellular calcium but does not seem to be related to the uptake of calcium by the acini.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D002217:Carbachol / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology*; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology
D001647:Bile Acids and Salts; D002217:Carbachol; D004492:Edetic Acid; D014700:Verapamil; D007770:L-Lactate Dehydrogenase; D000681:Amylases; D008274:Magnesium; D002118:Calcium