Modulation of luteinizing hormone secretion by estrogens in patients with Reifenstein's syndrome

The role of estrogens on gonadotropin secretion was assessed in two siblings with incomplete virilization syndrome type I due to partial androgen insensitivity (Reinfenstein's syndrome). Serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured before and after 100 micrograms LH-releasing hormone (RH) intravenous (IV) stimulation, as well as during long-term clomiphene citrate (CC) administration. Serum testosterone (T) and estrogens were determined before and during daily administration of human chronic gonadotropin (hCG) and also during the CC treatment. Basal levels of LH were elevated in both patients: 12.5 +/- 1.1 mIU in patient A and 19.8 +/- 1.8 mIU/ml in patient B. Conversely, FSH levels were within normal limits. Administration of LH-RH in both subjects induced a rise in LH levels, while FSH concentration showed no increase. The CC administration resulted in a significant (P less than 0.005) increment in serum LH levels without changes in FSH concentration. An important increase of serum T and estradiol (E2) levels was noted during CC administration; thus, in patient A those levels augmented from 20 to 48 ng/ml for T and from 78 to 220 pg/ml for E2; and patient B showed an increment from 20 to 35 ng/ml for T, and from 55 to 180 pg/ml for E2. The daily administration of hCG was followed by an increment in both T and E2 levels, which was of lesser degree for estrone concentration. These results suggest that endogenous estrogens, particularly E2, modulate LH secretion in patients with partial androgen insensitivity; however, it appears that estrogens had no physiologic effect on FSH secretion.