RESEARCH ARTICLE Inhibition of NOS-NO System Prevents Autoimmune Orchitis Development in Rats: Relevance of NO Released by Testicular Macrophages in Germ Cell Apoptosis and Testosterone Secretion

Background Although the testis is considered an immunoprivileged organ it can orchestrate immune re-sponses against pathological insults such as infection and trauma. Experimental autoim-mune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infil-trate the interstitium concomitantly with progressive germ cell degeneration and impaired steroidogenesis. Up-regulation of nitric oxide (NO)-NO synthase (NOS) system occurs, macrophages being the main producers of NO. Objective The aim of our study was to evaluate the role of NO-NOS system in orchitis development and determine the involvement of NO released by testicular macrophages on germ cell apo-ptosis and testosterone secretion. Method and Results EAO was induced in rats by immunization with testicular homogenate and adjuvants (