EFFECTS OF THE COCULTURE WITH HUMAN ENDOMETRIAL CELLS ON THE FUNCTIONOF SPERMATOZOA FROM SUBFERTILE MEN

Objective: To evaluate the effects of a coculture with human endometri al cells on the function of spermatozoa from samples obtained from inf ertile couples. Design: In a prospective study, human spermatozoa sele cted by swim-up from fresh samples were cultured on human endometrial feeder layers. Thereafter, their viability, motility, acrosome integri ty, and ability to penetrate zona-free hamster oocytes were evaluated. Spermatozoa from the same samples incubated under the same conditions but in the absence of endometrial cells, as well as in the medium pre viously spent for cell culture, were used as controls. Setting: Androl ogy Laboratory of the Infertility Center of San Raffaele Hospital. Pat ients: Spermatozoa were obtained from 17 infertile men attending the I nfertility Center at our hospital. Results: Spermatozoa incubated in t he presence of endometrial cell feeder layers did not differ from cont rols with regard to their viability or motility. Conversely, the perce nt spontaneous acrosome reactions after 18 hours of incubation was sig nificantly higher for spermatozoa cocultured (19.7 +/- 2.2 versus 11.2 +/- 1.9; mean +/- SE). The mean number of spermatozoa penetrating ham ster oocytes was also significantly improved (1.24 +/- 0.3 versus 0.68 +/- 0.24). This effect did not seem to be solely due to the secretion of soluble factors by endometrial cells in the medium, in that sperma tozoa incubated in the medium spent for endometrial cell culture had a similar acrosome reaction percentage but a lower rate of hamster egg penetration. Conclusions: The coculture with human endometrial cells a ppeared to be beneficial for improving the sperm function. This effect partially may be due to the secretion of steroids in the medium, whic h increases the quota of spontaneous acrosome reaction and in part due to the direct contact of cells with spermatozoa, maybe for the detoxi fication of the medium or the release of trophic factors. Coculture mi ght be a promising approach to preparing spermatozoa for assisted fert ilization in cases of subfertile males.