Human Reproduction vol.7 no.7 pp 987-990, 1992
Effects of indoleamines on sperm motility in vitro
Tiilay deal irez1, Hiilya $enol, Meryem Alagoz, Cavidan Basmaciogullari, Feyhan Turan, Dilhan Kuru and Erdogan Ertiingealp University of Istanbul, Cerrahpa§a Medical Faculty, Dept. of Gynaecology and Obstetrics, Andrology Lab., Cerrahpasa 34301 P.K.15, Istanbul, Turkey 'To whom correspondence should be addressed
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 motuity. 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. Key words: in wrro/indoleamines/sperm motility
Introduction The regulatory influence of the pineal secretory products on the neuroendocrine reproductive axis of a variety of experimental animals is well documented and has served as the basis for classifying the pineal gland as an endocrine organ (Irez-Ocal et al., 1989). For many years, there has been speculation that the pineal gland plays a role in human reproductive physiology (Vaughan et al., 1978). Although the role of indoleamines in humans has not yet been clarified, there are observations suggesting that it is involved in regulating the release of pituitary hormones and other endocrine functions (Vaughan et al., 1978; Silman and Edvards, 1980). Since the pineal indolic compounds melatonin, 5-methoxytryptophol and 5-methoxyindole-3-acetic acid have been extensively reported to inhibit some secretions or actions of hormones related to reproduction, the effects were studied of melatonin and other indoleamines on sperm motility of normozoospermic samples (Reiter et al., 1975; Martin et al., 1977; Mas and Oaknin, 1977; Pevetet al., 1981; Irez-Ocal et al., 1989). Materials and methods This study was performed with portions of semen from men undergoing semen analysis within thereproductiveendocrinology © Oxford University Press
division of Cerrahpasa Medical Faculty, Department of Gynaecology and Obstetrics. All men had normal seminal analysis according to World Health Organization criteria. Semen was collected by masturbation into sterile plastic containers from 25 normozoospermic men (sperm concentration >20 X lC^/ml, motility ^ 4 0 % , mean velocity >20/im/s and ^60% oval forms). Fresh ejaculates were allowed to liquefy at room temperature for 2 0 - 3 0 min and motile spermatozoa were obtained by swim-up migration. Earle's balanced salt solution was used as the incubation medium and included (20%) heat inactivated fetal cord serum. For the swim-up procedure, each semen sample was washed twice in ten volumes of Earle's solution and centrifuged at 1000 r.p.m. for 10 min. The final pellet was resuspended for swim-up and after a 1 or 2 h incubation, spermatozoa were recovered in the supernatant. An assessment of initial motility, velocity and viability was performed. Each specimen was analysed by multiple exposure photography and was divided into eleven 30 /tl aliquots. Indoles were dissolved in 100 /il absolute ethanol and diluted with Earle's balanced salt solution (1 mg/25 ml). Indoles were added to nine of the aliquots at final concentrations of 150, 300 or 450 pg/ml. The first aliquot (EBSS) and the second aliquot (EBSS+alcohol) served as the controls. Each sample was incubated in a CO2 incubator at 37°C for 1 or 2 h. The percentage motility and mean sperm velocity were assessed by multiple exposure photography at 0, 60 and 120 min (Elliot et al., 1973). Statistical analysis of the differences between multiple means for both percentage motility and velocity was performed by analysis of variance and Student's Mest. A probability