title: Manganese attenuates secretagogue-mediated phospholipid hydrolysis in AR42J cells.
abstract: The effects of cholecystokinin octapeptide (CCK8), bombesin and manganese (Mn2+) on phosphatidylinositol-4,5-bisphosphate (PIP2) hydrolysis were studied in AR42J cells. One-half maximal stimulation of inositol monophosphate (InsP1) accumulation occurred at either 5 nM CCK8 or 5 nM bombesin, and maximal stimulation occurred at 30 nM for each agonist. Mn2+ did not alter basal PIP2 hydrolysis. However, addition of Mn2+ 5 min prior to stimulation with either CCK8 or bombesin for 60 min significantly attenuated [3H]InsP1 accumulation. Following brief periods of incubation with CCK8 (15 sec) Mn2+ significantly reduced inositol tris- and tetrakisphosphate accumulation. These data suggest that Mn2+ may participate in the regulation of CCK8- and bombesin-mediated generation of phosphoinositides.
authors.affiliation: University of Arizona College of Medicine, Dept. of Microbiology, Tucson.
authors.forename: S A
authors.initials: SA
authors.lastname: Siwik
authors.forename: M
authors.initials: M
authors.lastname: Korc
mesh_terms: D000818:Animals; D001839:Bombesin / Q000494:pharmacology; D002460:Cell Line; D006868:Hydrolysis; D007295:Inositol Phosphates / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology*; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D012844:Sincalide / Q000494:pharmacology
chemical_list: D007295:Inositol Phosphates; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D008345:Manganese; D012844:Sincalide; D001839:Bombesin