Protein patterns of human uterine flushings collected at various stages of the menstrual cycle.

Uterine flushings and plasma collected from normal, parous women at various stages of the menstrual cycle were subjected to gel electrophoresis. The protein profiles of the flushings differed in many instances from the plasma pattern by the presence of between one and eleven non-plasma proteins. The distribution of the major non-plasma proteins during the menstrual cycle was not statistically significant but that of a pretransferrin, observed in uterine flushings and in peritoneal fluid, was significant. However, the appearance of this protein band could not be related to a particular phase of the cycle, and hence to a specific hormonal condition.