title: Fusion of prostasomes to human spermatozoa stimulates the acrosome reaction.
abstract: OBJECTIVE
  To determine the effect of the fusion of prostasomes to spermatozoa on the acrosome reaction.
  
  
  METHODS
  In vitro study of human spermatozoa.
  
  
  METHODS
  Healthy volunteers in an academic research environment.
  
  
  METHODS
  Healthy volunteer men, 25 to 35 years old.
  
  
  METHODS
  Human semen was fractionated into spermatozoa and prostasomes. Fusion of prostasome to spermatozoa was performed at pH 5.5. Progesterone (1 microM) was added when required.
  
  
  METHODS
  Evaluation of the acrosome reaction by fluorescence microscopy.
  
  
  RESULTS
  The percentage of spontaneously acrosome-reacted cells was very low unless the Ca(2+)-ionophore A 23187 was added. The treatment of spermatozoa with 1 microM of progesterone scarcely affected the acrosome reaction; a pretreatment in conditions permitting fusion increased it. The addition of progesterone to prostasome-fused spermatozoa further increased the extent of the acrosome reaction.
  
  
  CONCLUSIONS
  The H(+)-dependent fusion with prostasomes makes spermatozoa more sensitive to the effect of progesterone on acrosome-reaction induction.
authors: Department of Biochemical Sciences and Molecular Biotechnology, University of Perugia, Perugia, Italy.
authors: Carlo A
authors: CA
authors: Palmerini
authors: Carla
authors: C
authors: Saccardi
authors: Enrico
authors: E
authors: Carlini
authors: Roberto
authors: R
authors: Fabiani
authors: Giuseppe
authors: G
authors: Arienti
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology*; D000001:Calcimycin / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D008561:Membrane Fusion; D011374:Progesterone / Q000494:pharmacology; D011467:Prostate / Q000378:metabolism*; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
chemical_list: D007476:Ionophores; D000001:Calcimycin; D011374:Progesterone