INVESTIGADORES
FAILLACE Maria paula
artículos
Título:
Melatonin effect on the cyclic GMP system in the golden hamster retina.
Autor/es:
FAILLACE MP, KELLER SARMIENTO MI, ROSENSTEIN RE
Revista:
BRAIN RESEARCH
Editorial:
Elsevier
Referencias:
Año: 1996 vol. 711 p. 112 - 117
ISSN:
0006-8993
Resumen:
Melatonin effect on retinal cyclic GMP accumulation, guanylate cyclase
activity, cyclic GMP content and cyclic GMP phospho-diesterase activity
was examined in the Syrian hamster retina. Melatonin increased
significantly cyclic GMP accumulation at picomolar concentrations and
in a time-dependent manner. The kinetic analysis of guanylate cyclase
activity revealed a significant increase of both apparent Vmax and
K(m), induced by 10 nM melatonin. The effect of melatonin was higher in
the absence, than in the presence of the phoshodiesterase inhibitor
(IBMX), suggesting an effect on cyclic GMP catabolism.
Phosphodiesterase activity was significantly decreased by melatonin.
The results show a dual effect of melatonin on cyclic GMP levels, i.e.
by increasing the synthesis and inhibiting the degradation, both
resulting in an increase of cyclic GMP levels. Taking into account the
key role of cyclic GMP in visual mechanisms, the results would suggest
the participation of melatonin in retinal physiology.