Extracellular ATP and bradykinin increase cGMP in vascular endothelial cells via activation of PKC.
Vasodilation by agents such as bradykinin and ATP is dependent on nitric oxide, the endothelium-dependent relaxing factor (EDRF). The release of EDRF results in elevation of cGMP in endothelial and smooth muscle cells (9). The signaling pathway that leads to increases in cGMP is not completely understood. The role of protein kinase C (PKC) in the elevation of cGMP induced by ATP and bradykinin was studied in cultured porcine aortic endothelial cells, by measuring PKC phosphorylation of a substrate and by measuring cGMP levels by radioimmunoassay. Extracellular ATP and bradykinin simultaneously elevated cGMP levels and PKC activity. The PKC inhibitors staurosporine, calphostin C, and Cremophor EL (T. Tamaoki and H. Nakano. Bio/Technology 8: 732-735, 1990; F. K. Zhao, L. F. Chuang, M. Israel, and R. Y. Chuang. Biochem. Biophys. Res. Commun. 159: 1359-1367, 1989) prevented the elevation of cGMP elicited by ATP and reduced that produced by bradykinin. Cremophor did not affect the elevation of cGMP by nitroprusside, an agent that directly increases guanylate cyclase activity (9). The PKC activator phorbol 12-myristate 13-acetate, but not a phorbol ester analog inactive on PKC, also elevated cGMP levels. These results suggest that EDRF agonists elevate cGMP in endothelial cells via PKC stimulation.
Instituto de Investigaciones Cardiológicas, Facultad de Medicina, Universidad de Buenos Aires, 1122 Buenos Aires, Argentina.
A F
AF
Castro
C
C
Amorena
A
A
Müller
G
G
Ottaviano
M T
MT
Tellez-Iñon
A C
AC
Taquini
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic; D001920:Bradykinin / Q000494:pharmacology*; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005333:Fetus; D007700:Kinetics; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology; D010703:Phorbol Esters / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D009281:Naphthalenes; D010703:Phorbol Esters; D014665:Vasodilator Agents; C061465:calphostin complex; C008876:phorbol-12,13-didecanoate; D009569:Nitric Oxide; C022131:cremophor; D011092:Polyethylene Glycols; D000255:Adenosine Triphosphate; D011493:Protein Kinase C; D006152:Cyclic GMP; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate; D001920:Bradykinin; D019331:NG-Nitroarginine Methyl Ester