title: 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.
abstract: BACKGROUND
  Although the testis is considered an immunoprivileged organ it can orchestrate immune responses against pathological insults such as infection and trauma. Experimental autoimmune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infiltrate 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 apoptosis and testosterone secretion.
  
  
  RESULTS
  EAO was induced in rats by immunization with testicular homogenate and adjuvants (E group) and a group of untreated normal rats (N) was also studied. Blockage of NOS by i.p. injection of E rats with a competitive inhibitor of NOS, L-NAME (8mg/kg), significantly reduced the incidence and severity of orchitis and lowered testicular nitrite content. L-NAME reduced germ cell apoptosis and restored intratesticular testosterone levels, without variations in serum LH. Co-culture of N testicular fragments with testicular macrophages obtained from EAO rats significantly increased germ cell apoptosis and testosterone secretion, whereas addition of L-NAME lowered both effects and reduced nitrite content. Incubation of testicular fragments from N rats with a NO donor DETA-NOnoate (DETA-NO) induced germ cell apoptosis through external and internal apoptotic pathways, an effect prevented by N-acetyl-L-cysteine (NAC). DETA-NO inhibited testosterone released from Leydig cells, whereas NAC (from 2.5 to 15 mM) did not prevent this effect.
  
  
  CONCLUSIONS
  We demonstrated that NO-NOS system is involved in the impairment of testicular function in orchitis. NO secreted mainly by testicular macrophages could promote oxidative stress inducing ST damage and interfering in Leydig cell function.
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Jarazo Dietrich
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Mónica Irina
authors.initials: MI
authors.lastname: Fass
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Patricia Verónica
authors.initials: PV
authors.lastname: Jacobo
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Cristian Marcelo Alejandro
authors.initials: CM
authors.lastname: Sobarzo
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Livia
authors.initials: L
authors.lastname: Lustig
authors.affiliation: Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: María Susana
authors.initials: MS
authors.lastname: Theas
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000276:Adjuvants, Immunologic; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D018920:Coculture Techniques; D045424:Complex Mixtures; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006801:Humans; D007985:Leydig Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007986:Luteinizing Hormone / Q000097:blood / Q000235:genetics; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D009920:Orchitis / Q000139:chemically induced / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013094:Spermatozoa / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013739:Testosterone / Q000096:biosynthesis / Q000378:metabolism; D014226:Triazenes / Q000494:pharmacology
chemical_list: C105351:1-hydroxy-2-oxo-3,3-bis(2-aminoethyl)-1-triazene; D000276:Adjuvants, Immunologic; D045424:Complex Mixtures; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D014226:Triazenes; D009569:Nitric Oxide; D013739:Testosterone; D007986:Luteinizing Hormone; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D019331:NG-Nitroarginine Methyl Ester; D000111:Acetylcysteine