Progesterone induces human sperm chemotaxis.

OBJECTIVE

To characterize the molecular nature of the chemotactic signal for sperm contained in human follicular fluid (FF).

DESIGN

Follicular fluid was fractionated and several procedures were followed to the physicochemical initial characterization of sperm chemotactic compound(s).

MAIN OUTCOME MEASURE

Relative chemotactic activity of each fraction was measured in a double chamber device.

RESULTS

Sperm chemotaxis was found to be associated with a lipid-like molecule extracted from FF. Several steroids were assayed individually and only P showed sperm chemotactic properties in dose-response curves.

CONCLUSIONS

In this paper we present experimental evidence to support the hypothesis that P, the main steroid component of FF, is a mediator of sperm chemoattraction in human beings.