Effect of melatonin on vascular responses of porcine ciliary arteries.
Curr Eye Res
; 24(4): 313-7, 2002 Apr.
Article
em En
| MEDLINE
| ID: mdl-12324871
ABSTRACT
PURPOSE:
To investigate the effect of melatonin on isolated porcine ciliary arteries.METHODS:
Isolated porcine ciliary arteries were suspended in myograph chambers filled with modified Krebs-Ringer solution (37 degrees C; 95% O2/5% CO2) for isometric tension recording.RESULTS:
In quiescent porcine ciliary arteries with endothelium, melatonin (10(-11)--10(-5) M) evoked no change in vascular tone. The highest concentration of melatonin (10(-4 ) M) evoked a small but significant contraction. In vessels precontracted with U-46619 (10(-7) M), increasing concentrations of melatonin (10(-11)--10(-5) M) did not evoke a response. In precontracted arteries with endothelium, contractile response of vascular smooth muscle to increasing concentrations of serotonin (10(-10)--10(-5) M) and noradrenaline (10(-10)--10(-5) M) was reduced after preincubation with melatonin (10(-4) M). Melatonin (10(-4) M) did not alter the response to endothelin-1 (10(-10)--10( -7) M) and U-46619 (10(-10)--10(-6 ) M) in precontracted arteries with endothelium.CONCLUSION:
These findings demonstrate that melatonin attenuates the effect of serotonin and noradrenaline and is itself a mild vasoconstrictor in porcine ciliary arteries. The role of melatonin in human ocular circulation remains to be established.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vasoconstritores
/
Artérias Ciliares
/
Melatonina
Limite:
Animals
Idioma:
En
Revista:
Curr Eye Res
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Suíça