title: Further evidence from an elastic artery that angiotensin II amplifies noradrenaline-induced contraction through activation of protein kinase C.
abstract: Angiotensin II (AII, 0.1 nM) increased concentration dependently the sensitivity of rabbit aortic rings to low concentrations of noradrenaline. This was not associated with increases in noradrenaline-induced 45Ca2+ uptake or efflux and was prevented by the protein kinase C (PKC) inhibitors staurosporine (0.01 microM) and calphostin C (0.1 microM). Pretreatment of the rings with PMA (phorbol-12-myristate-13-acetate, 0.1 and 1 microM, 24 h at 4 degrees C) abolished the potentiation phenomenon. We conclude that AII potentiation of noradrenaline-induced vascular tone may be due to a PKC-mediated increase in intracellular sensitivity of the contractile apparatus to Ca2+.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009281:Naphthalenes; D009638:Norepinephrine / Q000494:pharmacology*; D011083:Polycyclic Compounds / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011817:Rabbits; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D000470:Alkaloids; D009281:Naphthalenes; D011083:Polycyclic Compounds; C061465:calphostin complex; D000804:Angiotensin II; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D009638:Norepinephrine