title: Sperm lipid peroxidation and pro-inflammatory cytokines.
abstract: OBJECTIVE
  To investigate if interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha) are able to stimulate the level of lipid peroxidation of sperm membranes, either alone or in the presence of leukocytes.
  
  
  METHODS
  Semen samples from normozoospermic donors were prepared by density gradient. The sperms were exposed to the indicated cytokines, at physiological and infection-inflammation concentrations, in the absence or presence of leukocytes. Lipid peroxidation of the sperm membranes was determined by measuring malondialdehyde (MDA) and 4-hydroxialkenals (HAE) formation.
  
  
  RESULTS
  TNF-alpha, IL-8 and IFN-gamma increased the level of sperm membrane lipid peroxidation when tested at physiological concentrations. At infection-inflammation concentrations, only IL-8 was able to produce a higher effect. When assayed in the presence of leucocytes, IL-8 and TNF-alpha showed a higher effect at infection-inflammation concentrations than at physiological concentrations. Finally, IL-8 showed a higher effect in the presence of leukocytes than in their absence at both physiological and infection-inflammation concentrations. TNF-alpha also showed a higher effect when assayed in the presence of leukocytes than in their absence, but only at infection-inflammation concentrations. There was no effect of IL-6 or IL-10 in any of the tested conditions.
  
  
  CONCLUSIONS
  Several pro-inflammatory cytokines at physiological concentrations increase the level of lipid peroxidation of sperm membranes, which could be important for the sperm fecundation process. However, infection-inflammation concentrations of some cytokines, such as IL-8 and TNF-alpha, either alone or in the presence of leukocytes, could drive the lipid peroxidation of the spermatozoa plasma membrane to levels that can affect the sperm fertility capacity.
authors.affiliation: Departamento de Biología de Organismos, Universidad Simón Bolívar, Baruta, Venezuela.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martínez
authors.forename: Fulgencio
authors.initials: F
authors.lastname: Proverbio
authors.forename: María I
authors.initials: MI
authors.lastname: Camejo
mesh_terms: D016207:Cytokines / Q000032:analysis*; D006801:Humans; D007249:Inflammation / Q000503:physiopathology*; D007371:Interferon-gamma / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D007958:Leukocyte Count; D015227:Lipid Peroxidation; D008297:Male; D012016:Reference Values; D013094:Spermatozoa / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma