In vitro stimulation of human sperm motility by acetylcarnitine.

An increase in motility of ejaculated human spermatozoa was observed after the addition of acetylcaritine or carnitine. Similar results were also obtained in the diluted semen with 25--30% initial motilities. However, indirect evidence suggests that carnitine is converted to acetylcarnitine prior to its stimulatory action. In addition, this stimulation was shown to be the result of no increase in ionic strength nor any change in the levels of ATP.