L-Citrulline dilates rat retinal arterioles via nitric oxide- and prostaglandin-dependent pathways in vivo.
J Pharmacol Sci
; 127(4): 419-23, 2015 Apr.
Article
en En
| MEDLINE
| ID: mdl-25953269
ABSTRACT
L-Citrulline is an effective precursor of L-arginine produced by the L-citrulline/L-arginine cycle, and it exerts beneficial effects on the cardiovascular system by supporting enhanced nitric oxide (NO) production. NO dilates retinal blood vessels via the cyclooxygenase-mediated pathway. The purpose of this study was to examine the effects of L-citrulline on retinal circulation and to investigate the potential involvement of NO and prostaglandins in L-citrulline-induced responses in rats. L-Citrulline (10-300 µg kg(-1) min(-1), i.v.) increased the diameter of retinal arterioles without significantly changing mean blood pressure, heart rate, and fundus blood flow. The vasodilator response of retinal arterioles to l-citrulline was significantly diminished following treatment with N(G)-nitro-L-arginine methyl ester (30 mg/kg, i.v.), an NO synthase inhibitor, or indomethacin (5 mg/kg, i.v.), a cyclooxygenase inhibitor. In addition, α-methyl-dl-aspartic acid (147 mg/kg, i.v.), an inhibitor of argininosuccinate synthase, the rate-limiting enzyme for the recycling of l-citrulline to l-arginine, diminished the L-citrulline-induced retinal vasodilation. These results suggest that both NO- and prostaglandin-dependent pathways contribute to the L-citrulline-induced vasodilation of rat retinal arterioles. The L-citrulline/L-arginine recycling pathway may have more importance in regulating vascular tone in retinal blood vessels than in peripheral resistance vessels.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Arteria Retiniana
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Vasodilatación
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Transducción de Señal
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Prostaglandinas
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Citrulina
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Óxido Nítrico
Límite:
Animals
Idioma:
En
Revista:
J Pharmacol Sci
Asunto de la revista:
FARMACOLOGIA
Año:
2015
Tipo del documento:
Article