Nitric oxide synthase immunoreactivity and NADPH diaphorase staining are co-localised in neurons closely associated with the vasculature in rat and human retina

Abstract

Nitric oxide synthase (NOS) is widely distributed throughout the nervous system and is found in neurons which produce nitric oxide (NO). In attempting to elucidate the biological roles of NO in neurotransmission, vasodilation, and in neurodegeneration, nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry has been widely used. NADPHd histochemistry and NOS immunoreactivity (NOS-IR) have been assumed to stain the same population of neurons. However, there have been numerous reports which suggest that this may not always be the case, and in all neuronal populations investigated, the coincidence of NOS and NADPHd must be unequivocally demonstrated. We have examined NADP..