Localization of sex hormone-binding globulin mRNA expression in human uterine endometrium

To identify the dominant cell of sex hormone-binding globulin (SHBG) synthesis in human uterine endometrium, we investigated the expression of endometrial SHBG mRNA using Northern blot and in situ hybridization analyses. Expression of a single dominant SHBG mRNA was detected in uterine endometrium using Northern blot analysis. Additionally, SHBG mRNA expression was demonstrated by in situ hybridization in the glandular epithelial cells of the endometrium, but not in the stromal cells. Therefore, in the endometrial glandular epithelial cells, SHBG might be involved in the intracellular steroidal action, but not in the endometrial stromal cells. The SHBG-mediated effects on the endometrium appear to be heterogeneous.