Changes in acetylcholinesterase activity of mammalian spermatozoa during maturation

Acetylcholinesterase (AChE) activity of sperm recovered from the testes and several epididymal sites was studied in the boar, bull, and rat. AChE was highest in the bull spermatozoa followed by those of the rat and the boar. Between the testis and caput epididymis washed spermatozoa lost about 86% (bull), 60% (boar) or 32% (rat) in AChE activity while between the caput and cauda epididymides, a further loss of 28, 10, and 27% in the enzyme activity occurred in the respective species. Sperm AChE activity was negatively related to the development of sperm motility during sperm maturation and with sperm abnormality.