NADPH-d positive neurons of the lizard Podarcis s. sicula oviduct and their relationship to 17 beta-estradiol hormone

The distribution of nicotinamide adenine dinucleotide phosphate reduced dia phorase (NADPH-d) containing neurons was examined in the oviduct of the liz ard Podarcis s. sicula and the relationship between these neurons and 17 be ta -estradiol hormone was studied. NADPH-d-histochemistry and indirect immu nofluorescence method were applied to cryostat sections. NADPH-d-nerve stru ctures were found throughout the oviduct. Positive neurons were primarily l ocated in the reproductive oviduct. and were more numerous in the intermusc ular and circular muscle layers than in the mucosa. The vagina revealed a r eactive nerve population denser than elsewhere. The NADPH-d-positive neuron s densities and the 17 beta -estradiol plasma levels coincided throughout t he lizard sexual cycle. In addition, after 17 beta -estradiol treatments, n on-reproductive lizards showed an increase of NADPH-d neurons. We suppose t hat nitric oxide (NO) neurons play an estrogen-dependent role in the oviduc t muscle motility. (C) 2001 Elsevier Science Inc. All rights reserved.