Lack of nitric oxide- and guanosine 3 ': 5 '-cyclic monophosphate-dependent regulation of alpha-thrombin-induced calcium transient in endothelial cells of spontaneously hypertensive rat hearts

Citation
P. Failli et al., Lack of nitric oxide- and guanosine 3 ': 5 '-cyclic monophosphate-dependent regulation of alpha-thrombin-induced calcium transient in endothelial cells of spontaneously hypertensive rat hearts, BR J PHARM, 130(7), 2000, pp. 1468-1476
Citations number
31
Categorie Soggetti
Pharmacology & Toxicology
Journal title
BRITISH JOURNAL OF PHARMACOLOGY
ISSN journal
00071188 → ACNP
Volume
130
Issue
7
Year of publication
2000
Pages
1468 - 1476
Database
ISI
SICI code
0007-1188(200008)130:7<1468:LONOAG>2.0.ZU;2-5
Abstract
1 While the expression and/or activity of endothelial nitric oxide synthase CeNOS) has been characterized in spontaneously hypertensive (SHR) and norm otensive Wistar Kyoto rat (WKY) hearts, in coronary endothelial cells (ECs) from both strains, the effect of NO on intracellular calcium concentration ([Ca2+](i)) is still unknown. 2 Coronary microvascular ECs were isolated from SHR and WKY and characteriz ed. Immunocytochemistry and Western blot analysis showed that eNOS was simi larly expressed in ECs from both strains. 3 Measuring [Ca2+](i) by imaging analysis of fura-2-loaded cells, we demons trated that a-thrombin (3-180 U l(-1)) induced a superimposable dose-depend ent calcium transient in ECs from both strains. 4 In WKY ECs, S-nitroso-N-acetyl-DL-penicillamine (SNAP) dose-dependently ( 10 - 100 mu M) and 0.1 mu M atrial natriuretic factor (ANF) reduced the max imum and the decay time of alpha-thrombin-induced calcium transient. The in hibitory effects of SNAP and ANF were prevented by blocking cyclic GMP-depe ndent protein kinase. Non selective eNOS inhibitors prolonged the decay tim e of alpha-thrombin-induced calcium transient, while the selective inducibl e NOS inhibitor 1400W was ineffective. SNAP (100 mu M) and 0.1 mu M ANF inc reased cyclic GMP content up to 22.9 and 42.3 fold respectively. 5 In SHR ECs, alpha-thrombin-induced calcium transient was not modified by SNAP, ANF or eNOS inhibition. SNAP (100 mu M) and 0.1 mu M ANF increased cy clic GMP content up to 9.3 and 51 fold respectively. 6 In WKY ECs, SNAP dose-dependently (10 - 100 mu M) reduced also bradykinin -induced calcium transient, while in SHR ECs was ineffective. 7 We concluded that in SHR ECs, the cyclic GMP-dependent regulation of calc ium transient is lost.