title: Studies on the membrane integrity of human sperm treated with a new injectable male contraceptive.
abstract: BACKGROUND
  The aim of this study was to evaluate the integrity of sperm surface characteristics in the presence of a new male contraceptive, RISUG [1 mg styrene maleic anhydride (SMA)/100 microl dimethylsulphoxide (DMSO) in 1 ml sperm solution].
  
  
  METHODS
  Progressively motile human sperm were treated in vitro with RISUG. The cells were analysed for the release of 5'-nucleotidase (5'-NT) (a plasma membrane marker) using 3 mmol/l 5'-AMP and 3 mmol/l beta-glycerophosphate as substrates. Hyaluronidase (an acrosomal membrane marker) was analysed using hyaluronic acid as a substrate. The contents of free and total acrosin, and % proacrosin (all acrosome markers) were assayed using 0.5 mmol/l alpha-N-benzoyl-L-arginine ethylester (BAEE).
  
  
  RESULTS
  RISUG caused almost complete disintegration of the plasma membrane leading to significant (P < 0.0001) release of 5'-NT into the surrounding media. Complete dissolution of the acrosome with concomitant vesiculation of the membrane system, as judged from the loss of hyaluronidase, was observed. Total acrosin content in the sperm was also reduced to almost 10%, and proacrosin dropped to 13.2% in the presence of RISUG in comparison to 90.2% in control (P < 0.0001), indicating dispersion of acrosomal contents.
  
  
  CONCLUSIONS
  Under in vitro conditions, RISUG, at a concentration of 1 mg SMA dissolved in 100 microl of DMSO, caused significant damage to the acrosome and its contents, indicating loss of functional ability of sperm.
authors.affiliation: School of Medical Science and Technology, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: K
authors.initials: K
authors.lastname: Chaudhury
authors.forename: A K
authors.initials: AK
authors.lastname: Bhattacharyya
authors.forename: S K
authors.initials: SK
authors.lastname: Guha
mesh_terms: D000176:Acrosin / Q000037:antagonists & inhibitors / Q000378:metabolism; D000328:Adult; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D003272:Contraceptive Agents, Male / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008298:Maleates / Q000494:pharmacology*; D011091:Polyesters; D011137:Polystyrenes; D012997:Solvents; D013094:Spermatozoa / Q000187:drug effects* / Q000201:enzymology; D013343:Styrenes / Q000494:pharmacology*
chemical_list: D003272:Contraceptive Agents, Male; D004792:Enzyme Precursors; D008298:Maleates; D011091:Polyesters; D011137:Polystyrenes; D012997:Solvents; D013343:Styrenes; C440495:contraceptive agent, RISUG; D006821:Hyaluronoglucosaminidase; C022438:proacrosin; D000176:Acrosin; D004121:Dimethyl Sulfoxide