Immunocytochemical localization of nitric oxide synthase in the mammalian retina

The localization of nitric oxide synthase (NOS) was investigated by immunoc ytochemistry and immunoblotting using an antiserum against neuronal NOS in the rat, mouse, guinea pig, rabbit and cat retinae. Western blot analysis o f retinal tissue extracts showed that the NOS-immunoreactive band of 155 kD a was present in all species. In the rat, mouse, guinea pig and rabbit reti nae, two types of amacrine cells and a class of displaced amacrine cells we re consistently NOS-labeled. In the cat retina, unlike other mammals, one t ype of amacrine cells and two types of displaced amacrine cells showed NOS immunoreactivity. NOS immunoreactivity was further found in some bipolar ce lls of the rat and guinea pig, some interplexiform cells of the mouse, some photoreceptor cells of the rabbit and same Muller cells of the cat. (C) 19 99 Elsevier Science Ireland Ltd. All rights reserved.