Objective: To determine the proportion of human sperm that respond to progesterone and to determine their capacitation state. Design: The sperm population was separated according to motility by means of a Percoll density gradient; three subpopulations of low, medium, and high motility were obtained. Setting: University-based laboratory. Participant(s): Sperm samples from healthy donors with normal spermatogram values were used. Intervention(s): None. Main Outcome Measure(s): The percentage of viable spermatozoa that increased the intracellular [Ca2+](i) in response to progesterone was determined with a fluorescence-activated cell sorter (FACS). The percentage of capacitated spermatozoa was determined as the difference between with and without phorbol 12-myristate 13-acetate stimulus according to fluorescence microscopy and the FACS methods. Result(s): A significant linear relationship between the proportion of motile cells and the percentage of sperm that increases the [Ca2+](i) in response to progesterone was observed with or without previous phorbol 12-myristate 13-acetate treatment. The slope of the correlation equation corresponding to the phorbol 12- myristate 13-acetate treatment was significantly lower. In addition, a significant correlation between capacitation and motility was observed. Conclusion(s): It seems likely that the proportion of capacitated and progesterone-responding human sperm correlates with motility.
Giojalas, L. C. (1998). Correlation between response to progesterone and other functional parameters in human spermatozoa. Fertility and Sterility, 69(1), 107–111. https://doi.org/10.1016/S0015-0282(97)00441-X