Abstract
Cell functions are regulated by many materials existed in extracellular and intracellular environments. Hormone is one of materials regulated with cell functions. It has been accepted that several hormones regulates with reproductive functions of mammalians; for example fertilization, sexual maturation, spermatogenesis, reproductive rhythms and so on. On several previous studies, it was suggested that estrogen and progesterone were positively or negatively regulated with sperm functions such as acrosome reaction and capacitation. It was also investigated that melatonin was negatively regulated with acrosome reaction and qualities of sperm motility. We do not have well understood a regulatory mechanism of sperm function by hormone although several hormones regulated with sperm functions via non-genomic regulatory systems. Spermatozoon is male reproductive cell and consists of sperm head and flagellum. Spermatozoon swims using flagellum in order to transport male DNA existed in sperm head to an oocyte. Generally, translation of gene does not occur in spermatozoon. All sperm functions are regulated by only protein-protein interactions such as phosphorylation, dephosphorylation and so on.
In the present study, non-genomic regulatory systems of sperm functions by hormones were examined using hyperactivation as functional marker. Progesterone and melatonin significantly increased hyperactivation. Progesterone affected spermatozoon via membrane receptors thought a novel non-genomic system. Melatonin also affected spermatozoon via receptor although receptor types were not clear. Many sperm functions are regulated by protein phosphorylation. Progesterone significantly increased tyrosine phosphorylation.
