OBJECTIVE

The early events of reproduction involve a carefully modulated complex system of oocyte maturation, fertilization, and proliferation. The aim of the study was to measure the presence of cytokines, namely interleukin 1 (IL-1), interleukin 6 (IL-6), colony-stimulating factor 1 (CSF-1), and tumor necrosis factor (TNF) in the conditioned medium (CM) of the oocytes, granulosa cells, cumulus cells, one to eight-cell embryos and sperm.

METHODS

The material was obtained from men and women undergoing in vitro fertilization therapy.

METHODS

We hypothesized that cytokines might affect embryonic growth and differentiation as they show a pleotropic effect on immune cells.

RESULTS

All these cytokines are present in significant quantities in the CM and were shown to be expressed in a sequential manner; thus, some are present in the oocyte and its vestment, the corona-cumulus complex (IL-1, IL-6, and CSF-1), whereas TNF appears only at the stage of six to eight-cell embryos. Inflammatory cytokines could not be detected in sperm samples.

CONCLUSIONS

It is possible that these cytokines have a role in the regulation of embryonic development, maternal immunological recognition of pregnancy, and maintenance of proper hormonal environment.