Differential effects of protein kinase C activation on catecholamine secretions evoked by stimulations of various receptors in the rat adrenal medulla.
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.
Warashina
A
A
Department of Physiology, Niigata University School of Medicine, Japan.
Fujiwara
N
N
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
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