title: Methotrexate induces germ cell apoptosis and impairs spermatogenesis in a rat.
abstract: OBJECTIVE
  The primary toxic effects of methotrexate (MTX) are myelosuppression and/or intestinal mucositis. The objective of the present study is to investigate the effect of MTX on germ cell apoptosis and spermatogenesis in a rat.
  
  
  METHODS
  Male Sprague-Dawley rats were divided into three experimental groups: control rats treated with vehicle; MTX-2 rats treated with one dose (20 μg/kg) of MTX given IP and killed on the second day; and MTX rats treated with IP MTX (20 μg/kg) and killed on day 4. Johnsen's criteria and the number of germinal cell layers in the testes were used to categorize the spermatogenesis. TUNEL assay was used to determine germ cell apoptosis. Western blotting was used to determine Bax and Bcl-2 protein levels. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with p less than 0.05 considered statistically significant.
  
  
  RESULTS
  On day 2, MTX-treated animals demonstrated minimal changes in the histological parameters of spermatogenesis, but germ cell apoptosis increased significantly (threefold increase, p = 0.002) compared to control rats. On day 4, MTX-treated rats demonstrated a trend toward a decrease in germ cell apoptosis, compared to day 2, and showed histological signs of impaired spermatogenesis (decreased number of germ cell layers and Johnsen's criteria). A significant increase in cell apoptosis in MTX-treated rats was correlated with higher Bax/Bcl-2 protein levels.
  
  
  CONCLUSIONS
  MTX induced germ cell apoptosis and impaired spermatogenesis in rat testes.
authors.affiliation: The Bruce Rappaport Faculty of Medicine, Laboratory of Intestinal Adaptation and Recovery, Technion-Israel Institute of Technology, Haifa, Israel. igor-dr@internet-zahav.net
authors.forename: Igor
authors.initials: I
authors.lastname: Sukhotnik
authors.forename: Omri
authors.initials: O
authors.lastname: Nativ
authors.forename: Alex
authors.initials: A
authors.lastname: Roitburt
authors.forename: Daniel
authors.initials: D
authors.lastname: Bejar
authors.forename: Arnold G
authors.initials: AG
authors.lastname: Coran
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Mogilner
authors.forename: Ofer
authors.initials: O
authors.lastname: Nativ
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000633:toxicity*; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western / Q000379:methods; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling / Q000379:methods; D008297:Male; D008727:Methotrexate / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013091:Spermatogenesis / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects*
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D008727:Methotrexate