title: Differential effects of protein kinase C activation on catecholamine secretions evoked by stimulations of various receptors in the rat adrenal medulla.
abstract: Catecholamine secretions during continuous receptor stimulations by histamine, muscarine and bradykinin in the rat adrenal medulla commonly consisted of two phases, a transient initial secretion followed by a sustained secretion. On activating protein kinase C (PKC) by phorbol dibutyrate (PDBu), both phases of histamine-evoked secretion were inhibited whereas the initial phase alone was inhibited with muscarine. In contrast, bradykinin-evoked secretion as a whole was potentiated. Similar modes of modulations were exhibited when the secretions with these agonists were elicited in muscarine- or bradykinin-pretreated medullae in which PKC had been activated by endogenous processes. It is suggested that PKC may selectively affect the receptors or/and GTP-binding proteins to cause the differential effects on the secretory response in the rat adrenal medulla.
authors.affiliation: Department of Physiology, Niigata University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Warashina
authors.forename: N
authors.initials: N
authors.lastname: Fujiwara
mesh_terms: D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism* / Q000502:physiology; D004224:Diterpenes; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009116:Muscarine / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000187:drug effects*; D013729:Terpenes / Q000494:pharmacology
chemical_list: D002395:Catecholamines; D004224:Diterpenes; D010703:Phorbol Esters; D010716:Phosphatidylinositols; D011956:Receptors, Cell Surface; D013729:Terpenes; C008876:phorbol-12,13-didecanoate; C011309:mezerein; D015240:Phorbol 12,13-Dibutyrate; D009116:Muscarine; D006632:Histamine; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D001920:Bradykinin