Carnosine facilitates nitric oxide production in endothelial f-2 cells.
We examined the effect of carnosine (beta-alanyl-histidine) on nitric oxide (NO) production and endothelial NO synthase (eNOS) activation in endothelial F-2 cells. Carnosine enhanced NO production in a dose-dependent manner, and the stimulatory effect of carnosine was observed at concentrations exceeding 5 mM. The carnosine-stimulated NO production was inhibited by N(G)-nitro-L-arginine methyl ester, but not by N(G)-nitro-D-arginine methyl ester. In contrast, beta-alanine, histidine (carnosine components) and anserine (N-methyl carnosine) failed to increase NO production. Carnosine had no effect on NO production for the initial 5 min, but thereafter resulted in a gradual increase in NO production up to 15 min. Carnosine did not induce phosphorylation of eNOS at Ser1177. The carnosine-induced increase in NO production was observed even when extracellular Ca2+ was depleted by ethylene glycol bis(2-aminoethyl ether)-N,N,N'-N'-tetraacetic acid however, the effect was abolished upon depletion of intracellular Ca2+ by BAPTA. After F-2 cells were incubated with carnosine for 4 min, intracellular Ca2+ concentration gradually increased. The carnosine-induced increase in intracellular Ca2+ concentration occurred even in the absence of extracellular Ca2+. These results indicate that carnosine facilitates NO production in endothelial F-2 cells. It is also suggested that eNOS is activated by Ca2+, which might be released from intracellular Ca2+ stores in response to carnosine.
Takahashi
Satoru
S
First Department of Biochemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, Yoshino, Nobeoka, Miyazaki 882-0072, Japan. satorutaka@phoenix.ac.jp
Nakashima
Yukiko
Y
Toda
Ken-Ichi
K
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002336:Carnosine / Q000494:pharmacology*; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*
D009569:Nitric Oxide; D002336:Carnosine; D002118:Calcium