Further indications of the multicomponent nature of the acrosome reaction-inducing substance of human follicular fluid.
Human follicular fluid (hFF), which has been treated with either unspecific proteases or dextran-coated charcoal (DCC) to remove proteins and/or steroids, cannot successfully induce the acrosome reaction (AR). After the removal of steroids, AR-inducing activity can be restored to hFF by supplementation with exogenous progesterone, but only in the presence of intact protein. Gel filtration experiments with 3H-progesterone-labelled hFF showed elution of the radioactive signal in the high molecular weight range, corresponding to bound progesterone. AR-inducing activity was seen in exactly the same fraction. Based on these results, the acrosome reaction-inducing substance (ARIS) appears to be a complex of progesterone and a progesterone-binding protein, which was shown to be identical with the plasma protein corticosteroid-binding globulin (CBG) by immunological techniques. AR induction was only observed in the presence of both CBG and progesterone, suggesting a combined effect of the two components.
Fehl
P
P
Department of Dermatology and Andrology, Justus-Liebig University, Giessen, Germany.
Miska
W
W
Henkel
R
R
D000177:Acrosome / Q000187:drug effects*; D001826:Body Fluids / Q000737:chemistry*; D002606:Charcoal; D010450:Endopeptidases / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects*; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D008561:Membrane Fusion / Q000187:drug effects*; D006080:Ovarian Follicle / Q000737:chemistry*; D011374:Progesterone / Q000302:isolation & purification / Q000494:pharmacology*; D011376:Progesterone-Binding Globulin / Q000302:isolation & purification / Q000494:pharmacology*
D046911:Macromolecular Substances; D011376:Progesterone-Binding Globulin; D002606:Charcoal; D011374:Progesterone; D010450:Endopeptidases