Abstract
On mammalian spermatozoa, capacitation is the essential process to fertile to the egg. Capacitated spermatozoa are generally acrosome reacted and are hyperactivated. Melatonin regulates seasonal reproductive functions. On previous studies, both of positive effects and negative effects of melatonin on sperm motility were reported.In the present study, effects of melatonin on sperm motility were examined. From results, melatonin enhanced hyperactivation of hamster spermatozoa. Effective concentrations were from 1pM to 1uM. Moreover, melatonin regulated hyperactivation through MT1 receptor. [J Physiol Sci. 2008;58 Suppl:S140]
