Effect of testosterone on the Connexin37 of sexual mature mouse cumulus oocyte complex

BACKGROUND Recent researches demonstrate that pre-treatment with androgen could increase retrieved oocytes number and clinical pregnancy rate in poor ovarian response (POR) patients. In view of gap junction intercellular communication (GJIC) is important for follicular growth, and androgen plays an important role in improving prognosis of POR patients, we speculate that androgen can increase the expression of connexin in follicle cells, and improve ovarian microenvironment, thus can promote ovarian response. The objective of the research is to study the effect of testosterone on connexin37 (Cx37) expression so as to provide theoretical basis for adding testosterone in treatment of POR. METHODS Cumulus-oocyte-cells (COCs) were collected from ICR mice ovaries, and were cultured in vitro for 48 h and then treated with testosterone (T) at various concentration. To assess whether the effect of androgen on Cx37 expression is mediated through androgen receptor (AR) pathway, COCs were cultured in vitro with Flutamide (androgen receptor antagonist). The expression of Cx37 was determined by western blot. RESULTS The expression of Cx37 in COCs which were treated with testosterone was higher than that of control group. There were significant differences (P < 0.001;<0.001;<0.001;<0.001). Cx37 increased with the elevated testosterone concentrations. Cx37 was lower in androgen receptor antagonist group (2.57 ± 0.12) than the corresponding testosterone concentrations group (4.42 ± 0.28). There were significant differences between two groups (P < 0.001). CONCLUSIONS There was close relationship between gap junction protein and ovarian response, which suggested that androgen could promote ovarian response by increasing the expression of Cx37 in follicle. Androgen plays an important role in ovarian response through the AR pathway and non-AR pathway.