The Mechanism of Chemical action of hCG

The concentration of intact human chorionic gonadotropin (hCG) and free β subunit (hCGβ) in sera and tissues of patients with gynecologic cancers was determined by radioimmunoassay. Intact hCG and free hCGβ levels were found to be elevated above the reference value (5mIU/ml) in sera of 50% of patients with epithelial ovarian cancer and in sera of 44% of patients with endometrial cancer. The sera intact hCG and free hCGβ levels were significantly higher in malignant then in non-malignant gynecologic tumors (P<0.05). Elevation intact hCG and free hCGβ above 5mIU/ml in tissues was found in 100% of patients with epithelial ovarian and endometrial cancers.The characteristics of the binding of 125I-hCG to hCG receptor in ovarian and uterine tumors homogenates were investigated using the radio receptor assay (RRA). Different factors affecting this binding were studied and the result showed that the maximum binding was achieved by using 500 and 700 µg protein of ovarian and uterine homogenate respectively 17 and 4 Pmol of 125I-hCG concentration for ovarian and uterine tumors respectively pH(7-7.4) for both tumors.