Conditions influencing human sperm capacitation and penetration of zona-free hamster ova.
The ability of human spermatozoa to penetrate zona-free hamster ova was examined following low-temperature capacitation (4 degrees C) in TES-Tris (TEST)-yolk buffer for periods of up to 66 hours. Results obtained from 66 individuals demonstrated that the number of penetrations per ova were increased by an average of 2.5-fold when spermatozoa were capacitated for 42 hours, as compared with 18 hours. Furthermore sperm with extremely poor penetration rates after 18-hour capacitation was often improved by longer capacitation periods. Patients from our infertility clinic with less than 20 X 10(6) spermatozoa/ml of ejaculate had significantly lower penetration rates when compared with patients and donors with greater than 20 X 10(6) spermatozoa/ml (P less than or equal to 0.001). The observed effects of TEST-yolk buffer appear to be related to its ability to preserve sperm motility over prolonged periods, during which increased capacitation of the total sperm population is achieved.
D000818:Animals; D002021:Buffers; D006224:Cricetinae; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D010063:Ovum / Q000502:physiology*; D011309:Preservation, Biological; D013075:Sperm Capacitation; D013076:Sperm Count; D013084:Sperm-Ovum Interactions
D002021:Buffers