Cell apoptosis in the testis of male rats is elevated by intervention with ß-endorphin and the mu opioid receptor.

ABSTRACT

ß-endorphin (ß-EP) is involved in the regulation of male germ cells; however, little is known about the effect of ß-EP on primary germ cells via opioid receptors. In this study, we first revealed significant cell apoptosis in the testis of male rats after ß-EP intervention. Subsequently, the expression of the mu opioid receptor (MOR) was detected in both Leydig cells (LCs) and spermatogonia (SGs) by fluorescence colocalization; overlapping signals were also detected in apoptotic cells. In addition, LCs and SGs were separated from the testis of male rats and primary cells were treated with ß-EP; this increased the mRNA levels of MOR and was accompanied by acute cell apoptosis. Our findings provide a foundation for the further study of apoptosis in reproductive cells regulated by ß-EP and the MOR receptor.