Inhibitory effects of calmodulin antagonists on isoproterenol- and dibutyryl cyclic AMP-stimulated amylase release from rat parotid acinar cells.
The effects of three calmodulin antagonists on rat parotid amylase release were investigated in vitro using a dispersed acinar cell preparation. The potent calmodulin antagonists, trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), inhibited both 1 microM isoproterenol (ISO)- and 1 mM dibutyryl cyclic AMP (DBcAMP)-stimulated amylase release in a dose-dependent manner at concentrations of 25-100 microM. The IC50 values for the ISO-stimulated amylase release were 22 microM with TFP and 42 microM with W-7, and the values for the DBcAMP-stimulated release were 25 microM and 48 microM, respectively. The weak calmodulin antagonist, N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), caused only slight inhibition at a concentration of 100 microM. These calmodulin antagonists only had a very small effect on the spontaneous release of lactate dehydrogenase. The results suggest that the calcium-calmodulin system may play a role in the exocytotic process of amylase release from the rat parotid gland.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D010306:Parotid Gland / Q000166:cytology / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013449:Sulfonamides / Q000494:pharmacology
D002147:Calmodulin; D013449:Sulfonamides; D003994:Bucladesine; C017967:W 7; D007770:L-Lactate Dehydrogenase; D000681:Amylases; D007545:Isoproterenol