title: Effect of acute immobilization stress with or without a heme oxygenase inducer on testicular structure and function in male albino rats.
abstract: BACKGROUND
  Stress disturbs homeostasis and may induce various disorders. Immobilization stress (IS) induced due to reduced area provided for mobility results in the imbalance of oxidant and antioxidant status. Stress leads to male reproductive dysfunction in many species, including rodents and humans. Induction of heme oxygenase-1 (HO-1), the rate limiting enzyme in heme degradation, increases host antioxidant defenses. We elucidated the protective role of induction of HO-1 by hemin on testicular damage induced by acute IS.
  
  
  METHODS
  Male albino rats were immobilized for a period of 6 h. Hemin was given for 3 consecutive days (40 μmol/kg/day, s.c.), before subjecting the animals to acute IS.
  
  
  RESULTS
  Upregulation of HO-1 following hemin administration was evidenced in our study by increasing carboxyhemoglobin (COHb) level. Histopathological evaluation confirmed that acute IS caused significant testicular tissue injury, which improves in groups pretreated with hemin. Acute IS also caused significant increases in serum catecholamines and corticosterone levels; however, it produced a significant decrease in testosterone level with non-significant changes in luteinizing hormone (LH) level. In addition, it was found that IS significantly increased testicular malondialdehyde (MDA) and decreased catalase activities. The HO-1 inducer (i.e., hemin) significantly decreased catecholamines and corticosterone levels, and increased testosterone and LH levels. Hemin also decreased testicular MDA and increased catalase activities significantly.
  
  
  CONCLUSIONS
  Induction of HO-1 protects the testes through its antioxidant and anti-inflammatory effects. Thus, it represents a potential therapeutic option to protect testicular tissue from detrimental effects of IS.
authors.forename: Neven Makram
authors.initials: NM
authors.lastname: Aziz
authors.forename: Merhan Mamdouh
authors.initials: MM
authors.lastname: Ragy
authors.forename: Mariana Fathy
authors.initials: MF
authors.lastname: Gayyed
mesh_terms: D000208:Acute Disease; D000818:Animals; D002263:Carboxyhemoglobin / Q000032:analysis; D002395:Catecholamines / Q000097:blood; D003345:Corticosterone / Q000097:blood; D004790:Enzyme Induction; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D006427:Hemin / Q000008:administration & dosage / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D020011:Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000201:enzymology / Q000473:pathology* / Q000503:physiopathology; D013737:Testis / Q000201:enzymology / Q000473:pathology* / Q000503:physiopathology; D013739:Testosterone / Q000097:blood
chemical_list: D002395:Catecholamines; D020011:Protective Agents; D013739:Testosterone; D006427:Hemin; D007986:Luteinizing Hormone; D002263:Carboxyhemoglobin; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D003345:Corticosterone