title: Quantitative differences in matrix metalloproteinase (MMP)-2, but not in MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 or TIMP-2, in seminal plasma of normozoospermic and azoospermic patients.
abstract: BACKGROUND
  Matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), have been detected in reproductive tissues and seminal plasma. The purpose of this study was to quantify MMP-2, MMP-9, TIMP-1 and TIMP-2 in human seminal plasma and to evaluate their association with sperm.
  
  
  METHODS
  Seminal plasma was analysed using ELISA assays for all four analytes in 12 normozoospermic and 12 azoospermic patients and then for MMP-2 only in another 114 men with azoospermia (n = 16), after vasectomy (n = 20) and with sperm counts within the following ranges: 0.3-19 x 10(6)/ml (n = 20), 20-23 x 10(6)/ml (n = 11), 49-57 x 10(6)/ml (n = 12), 96-110 x 10(6)/ml (n = 12), 139-161 x 10(6)/ml (n = 12) and 215-346 x 10(6)/ml (n = 11). Additional zymographic analyses using SDS-PAGE were performed.
  
  
  RESULTS
  All investigated MMPs and TIMPs were detected. MMP-9, TIMP-1 and TIMP-2 were not significantly different in normozoospermia and azoospermia. Only the MMP-2 concentration was significantly decreased in azoospermic compared with normozoospermic patients (mean +/- SD: 650.6 +/- 288.9 versus 1677 +/- 910.4 ng/ml respectively; P = 0.0002) and significantly correlated with the number of sperm (r = 0.54; P < 0.0001).
  
  
  CONCLUSIONS
  MMP-2 in seminal plasma was strongly correlated to the sperm count in a linear fashion. Its origin and potential function remain to be elucidated.
authors.affiliation: Department of Urology, University Hospital Charité, Humboldt University, Schumannstr 20/21, D -10117 Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Baumgart
authors.forename: S V
authors.initials: SV
authors.lastname: Lenk
authors.forename: S A
authors.initials: SA
authors.lastname: Loening
authors.forename: K
authors.initials: K
authors.lastname: Jung
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D008875:Middle Aged; D009845:Oligospermia / Q000378:metabolism* / Q000473:pathology; D009994:Osmolar Concentration; D012016:Reference Values; D012661:Semen / Q000737:chemistry*; D013076:Sperm Count; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000032:analysis*; D014659:Vasectomy
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9