cGMP stimulates endoplasmic reticulum Ca(2+)-ATPase in vascular endothelial cells.
Calcium is a crucial regulator of many physiological processes such as cell growth, division, differentiation, cell death and apoptosis. In this study, we examined the effect of cGMP on agonist-induced [Ca(2+)](i) transient in isolated rat aortic endothelial cells. 100 microM ATP was applied to the cells bathed in a Ca(2+)-free physiological solution to induce a [Ca(2+)](i) transient that was caused by Ca(2+) release from intracellular stores. cGMP, which was applied after [Ca(2+)](i) reached its peak level, accelerated the falling phase of [Ca(2+)](i) transient. Pre-treatment of the cells with CPA abolished the accelerating effect of cGMP on the falling phase of [Ca(2+)](i) transient. The effect of cGMP was reversed by KT5823, a highly specific inhibitor of protein kinase G. Taken together, these data suggest that cGMP may reduce [Ca(2+)](i) level by promoting Ca(2+) uptake through sarcoplasmic/endoplasmic reticulum ATPase and that the effect of cGMP may be mediated by protein kinase G.
Lau
Kin-Ling
KL
Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
Kong
Siu-Kai
SK
Ko
Wing-Hung
WH
Kwan
Hiu-Yee
HY
Huang
Yu
Y
Yao
Xiaoqiang
X
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic; D020013:Calcium Signaling; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002227:Carbazoles; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000494:pharmacology*; D004338:Drug Combinations; D004730:Endothelium, Vascular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000201:enzymology
D000470:Alkaloids; D002227:Carbazoles; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007211:Indoles; C073601:KT 5823; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D006152:Cyclic GMP; C000543:cyclopiazonic acid