Peritoneal fluid volume and levels of steroid hormones and gonadotrophins in peritoneal fluid of normal and norethisterone-treated women.

Peritoneal fluid and blood samples were collected at surgical sterilization from 30 untreated women at various stages of the luteal phase and from 43 women treated with 300 micrograms norethisterone daily. Levels of oestradiol, progesterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured. The highest peritoneal fluid volume (mean, 23.1 ml) was found in the early luteal phase (LH 0 to + 3) and the lowest (mean, 5.9 ml) in the late luteal phase (LH + 12 to menses). The norethisterone treatment diminished the formation of peritoneal fluid and the degree of inhibition was dependent upon the type of ovarian reaction to norethisterone. Progesterone and oestradiol levels were higher in peritoneal fluid compared to plasma throughout the luteal phase and during norethisterone treatment. A comparison of the levels of these steroids between untreated controls (LH + 8 to + 11) and norethisterone-treated women demonstrated that the progesterone levels in peritoneal fluid were highly reduced by norethisterone treatment, while the oestradiol levels were not affected. The FSH and LH levels were, in contrast to the steroid hormones, significantly lower in peritoneal fluid than in plasma, both in the untreated and the treated women. No differences in the FSH or LH levels between the untreated and treated women were found. The results indicate that the peritoneal fluid volume and the steroid hormone levels in peritoneal fluid vary with the stages of the luteal phase. Norethisterone treatment significantly reduced the peritoneal fluid volume as well as its progesterone concentration, whereas the oestradiol and gonadotrophin levels remained unchanged.