Effect of tubular and follicular fluids on acrosin activity and sperm motility

Acrosin activity is influenced by various inhibitors and stimulators. The present study investigated the ability of tubular and follicular fluid, taken at different stages of the menstrual cycle, to stimulate or inhibit acrosin activity. Endometrial histology and cervical mucus microscopy were used to ascertain the stage of the menstrual cycle. Normal human sperm were incubated separately with tubular and follicular fluid and then assessed for gross motility and acrosin activity. The fluids were also investigated immunoelectrophoretically against anti-alpha 1-antitrypsin and anti-alpha-2-macroglobulin. Nonovulatory tubular fluid inhibited acrosin activity, while ovulatory tubular fluid and that from the late proliferative stages lacked inhibition. Ovulatory follicular fluid acrosin activity, while nonovulatory follicular fluid did not. Ovulatory fluid also enhanced sperm motility. Immunoelectrophoresis of tubular fluid suggests the presence of some other potential inhibitors in addition to anti-alpha 1-antitrypsin. It would appear that tubular fluid maintains rather than activates sperm function, while follicular fluid at ovulation stimulates acrosin proteolytic activity and sperm motility.