Aging, hyaluronidase removal of the cumulus, and microinjection do not affect the sperm binding potential of human oocytes.
OBJECTIVE
We studied the influence of aging, hyaluronidase removal of the cumulus, and microinjection on the sperm binding potential of human oocytes under intact zona assay conditions to determine the safe use of unstored aged unfertilized ICSI oocytes on zona binding tests. Results were also compared with those for aged IVF oocytes under the same conditions.


METHODS
To avoid the large variation in sperm binding scores, we compared the ratios of the number of sperm bound to nontreated versus to treated oocytes. Treated oocytes were those whose zonae were exposed to hyaluronidase, an agent that decreases sperm binding. Experimental groups were fresh oocytes, experimentally aged fresh oocytes, fresh oocytes whose cumulus was removed either mechanically or with hyaluronidase, aged ICSI oocytes, and aged IVF oocytes.


RESULTS
Statistical analysis within and between groups showed that aging, previous insemination, cumulus removal by hyaluronidase, and microinjection did not affect the sperm binding potential of human oocytes.


CONCLUSIONS
As the zona binding ability of fresh and unfertilized aged ICSI oocytes is similar, they can be used safely in zona assays.
Barros
A
A
Laboratory of Medical Genetics, Faculty of Medicine, University of Porto, Portugal.
Sousa
M
M
Silva
J
J
Almeida
V
V
Rocha
E
E
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D015925:Cryopreservation; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa; D015044:Zona Pellucida / Q000187:drug effects / Q000502:physiology
D006821:Hyaluronoglucosaminidase