Effects of indoleamines on sperm motility in vitro

Indoleamines are products of the pineal gland and are postulated to play an antigonadotrophic role in the reproductive system of mammals. In humans, indoleamines have been localized in tissue fluids such as plasma, serum and cerebrospinal fluid. Because indoleamines exhibit antigonadotrophic properties, the authors examined whether these agents cause inhibitory effects on sperm motility. In this study, time and dose-dependent inhibition of sperm motility by indoleamines was observed. Furthermore, the presence of indoles in incubation medium decreased sperm velocity. These data suggest that the presence of high doses of indoles in reproductive fluids may inhibit sperm motility and velocity.