Extracellular ATP and Bradykinin increase c GMP in vascular endotelial cells via activation of PKC

CASTRO AF; AMORENA C; MÜLLER¨A; OTTAVIANO G; TELLEZ IÑON MT; TAQUINI AC

AMERICAN JOURNAL OF HYPERTENSION

NATURE PUBLISHING GROUP

Año: 1998 vol. 275 p. 113 - 119

0895-7061

Am J Physiol Cell Physiol 275: C113-C119, 1998; 0363-6143/98 $5.00   Vol. 275, Issue 1, C113-C119, July 1998 Extracellular ATP and bradykinin increase cGMP in vascular endothelial cells via activation of PKC A. F. Castro1, C. Amorena1,3, A. Müller1, G. Ottaviano1, M. T. Tellez-Iñon2, and A. C. Taquini1 1 Instituto de Investigaciones Cardiológicas, Facultad de Medicina, Universidad de Buenos Aires, 1122 Buenos Aires; 2 Instituto de Ingeniería Genética y Biología Molecular (Consejo Nacional de Investigaciones Científicas y Técnicas), 1428 Buenos Aires; and 3 Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Buenos Aires, Argentina 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. endothelium-dependent relaxing factor; phorbol ester; protein kinase C inhibitors