EFFECT OF NITROXYL ON THE HAMSTER RETINAL NITRIDERGIC PATHWAY

ROSENSTEIN RE, BARI SE, GOLDIN A, KELLER SARMIENTO MI, SAENZ DA

USA

Congreso; ASSOCIATION FOR RESEARCH IN VISION AND OPHTHALMOLOGY; 2004

PURPOSE: Nitrid oxide (NO) is generally accepted to be the final product of the nitric oxide synthase (NOS) activity. However, recent evidences suggest that under certain conditions, NOS produces nitroxyl (HNO) rather than NO, that it may be converted to its oxidized form by endogenous oxidants. In this context, the aim of the present work was to examine comparatively the effect of NO and HNO on the hamstr retinal nitridergic pathway. CONCLUSIONS: The differential effect of HNO and NO on several parameters suggests that, at least in the hamster retina, the conversion of the former to its oxidized form (if it occurs) is not complete. Furthermore, the present results indicate that both compounds inhibits its own synthesis by decreasing NOS activity and in the case of HNO also by reducing L-arginine availability. Since cGMP is one of the most relevant molecules in the phototransduction mechanism, HNO and NO could participate in the processing of retinal light information.