Studies on the nature of prolactin-like immunoreactivity in bromelin-treated cervical mucus.

Prolactin has been reported to be present in cervical mucus at concentrations higher than those found in blood. Our initial findings appeared to confirm this and the material fulfilled criteria of validity generally applied when an immunoassay is employed on a new biological matrix, i.e. parallelism and chromatographic identity. Further experiments demonstrated that prolactin concentrations in cervical mucus were less than 40 mU/L and the prolactin-like immunoreactivity originally detected was due to the action of the enzyme bromelin which was used to liquefy the mucus. Bromelin has a similar molecular weight to prolactin and appeared to digest prolactin tracer and reduce its ability to bind antiserum in a manner paralleling the effect of adding pituitary prolactin.