Patterns of changes in proteins in the peritoneal fluid of women during the periovulatory phase of the menstrual cycle.

During a laparoscopy that was performed between Day -6 and Day +9 of the cycle as related to the day of the LH peak (Day 0), the peritoneal fluid of 100 healthy female volunteers of proven fertility was collected and analysed. Peritoneal fluid volume and concentrations of total protein, albumin, alpha 1-, alpha 2-, beta- and gamma-globulins, IgA, IgG, IgM, haptoglobulin, acid-alpha 1-glycoprotein, alpha 1-antitrypsin, alpha 2-macroglobulin, C3-, C4- and C-reactive protein were determined. The peritoneal fluid volume and the concentrations of most proteins analysed showed an increase during the post-ovulatory phase of the period investigated. The peritoneal fluid:serum ratio of each individual protein showed a significant inverse correlation with its molecular weight. This confirms the assumption that peritoneal fluid is mainly an exudation product, most probably of ovarian origin.