The effect of Danazol on the circulating levels of 34K insulin-like growth factor-binding protein (PP12) and endometrial secretory protein PP14.

Twenty-four women, 11 with endometriosis and 13 with fibrocystic mastopathy, were treated with a medium dose (300-400 mg daily) of Danazol for 6 months. The circulating level of progesterone, the 34K insulin-like growth factor-binding protein (IGF-bp) and endometrial protein PP14 (placental protein 14) were measured by specific radioimmunoassays before and during treatment. The serum progesterone concentration decreased significantly during Danazol treatment, as did the serum levels of 34K IGF-bp and PP14. By the third month of therapy amenorrhoea was observed in 22 out of 24 women and this was accompanied by a further decline in the IGF-bp and PP14 levels. In light of the previous observations on the IGF-bp and PP14 synthesis by secretory endometrium and the fact that Danazol causes endometrial atrophy, these results suggest that Danazol treatment has an effect on endometrial protein secretion.