Selective expression of a progesterone receptor on the human sperm surface.
OBJECTIVE
To visualize progesterone (P) binding sites on the sperm surface, examine the relationship between hormone binding and hormone action (acrosome reaction), and determine the size of the hormone-responsive sperm subpopulation.


METHODS
Kinetic analysis of P binding was combined with the assessment of the hormone effect using a fluorescent acrosomal marker.


METHODS
Private hospital, medical research center, and a university-based andrological laboratory.


METHODS
Sperm samples were from healthy volunteers with normal spermiogram values.


METHODS
None.


METHODS
Progesterone binding was analyzed by fluorescence microscopy and flow cytometry using P coupled to fluorescein isothiocyanate-labeled bovine serum albumin. Tetramethylrhodamine isothiocyanate-labeled Pisum sativum agglutinin was used as acrosomal marker in double-labeling experiments.


RESULTS
After in vitro capacitation, only few spermatozoa (approximately 10%) were able to bind P to the cell surface, but most of these cells subsequently generated the acrosome reaction in response to hormone binding.


CONCLUSIONS
The expression of P receptor sites on the human sperm surface is a major factor controlling the P-induced acrosome reaction. Further studies are warranted to explore if defective expression of the receptor can compromise fertility.
Tesarik
J
J
Center for Reproductive Biology and medicine, American Hospital of Paris, Neuilly-sur-Seine, France.
Mendoza
C
C
Moos
J
J
Carreras
A
A
D001665:Binding Sites; D006690:Bisbenzimidazole; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D037102:Lectins; D008297:Male; D037121:Plant Lectins; D011374:Progesterone / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012235:Rhodamines; D012710:Serum Albumin, Bovine; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
D005456:Fluorescent Dyes; D037102:Lectins; D037121:Plant Lectins; D011980:Receptors, Progesterone; D012235:Rhodamines; C036292:pea lectin; D012710:Serum Albumin, Bovine; C009434:tetramethylrhodamine isothiocyanate; D011374:Progesterone; D016650:Fluorescein-5-isothiocyanate; D006690:Bisbenzimidazole