The Role of Pheromones in the Regulation of Estrous Cycle Duration in the Guinea Pig

Abstract

A decrease in estrous cycle duration, due to shortening of the period of vaginal closure (VC), has been observed in female guinea pigs exposed to the odor of urine from males of the same species. VC shortening was also observed in females exposed to the odor of female urine collected during the period of vaginal opening (VO). No alteration in VC duration occurred, however, in females exposed to urine collected in the 1st 7 days of VC. Also VC shortening did not occur in bulbectomized females exposed to the odor of male urine. Therefore, it was concluded that guinea pig urine, when highly concentrated, contains pheromones capable of shortening estrous cycle VC.

Effect of Electrochemical Stimulation in the Olfactory Bulbs on the Release of Gonadotropin Hormones in Rats

“…A fa cilitation of gonadotropin hormone secretion by olfactory stimuli could be inferred from studies showing that ablation of the olfactory bulbs in rats delayed the onset of sexual ma turity [filing, 1964;Orbach and filing, 1966], and that exposure of immature female mice to an adult male accelerates sexual maturation [Vanderberg, 1967[Vanderberg, , 1969Bronson, 1975], fa cilitates ovulation following treatment with either pregnant mare serum or human chori onic gonadotropin [Zarrow et al, 1973] and produces release of LH [Bronson and Des jardins, 1974], These latter effects appear to be associated with olfactory stimuli, since the esposure of immature mice to male urine also resulted in a release of LH [Bronson and Maruniak, 1976]. In adult animals, cyclic va ginal estrus was not altered after the removal of the olfactory bulbs of guinea pigs [Donovan andKopriva, 1965], rats [van der Werff ten Bosch andvan Beugen, 1960;Rosen et al, 1940;van Beugen and van der Werff ten Bosch, 1961], rabbits [Brooks, 1937;Sawyer, 1956] or fer rets [van der Werff ten Bosch, 1963], But shortening of estrous cycle's duration was ob served in female rats [Aron, 1973], guinea pigs [Jesel and Aron, 1976] and mice [Whitten, 1958] exposed to the odor of urine from males of the same species. Furthermore, olfactory bulb ablation caused a decrease of ovarian and uterine weights in mice [Whitten, 1956], but failed to affect ovulation induced by coitus in the rabbit [Brooks, 1937;Sawyer, 1956] and in the rat [Aron et al, 1970], al though Curry [1974] has reported that the removal of the olfactory bulbs in rats reduced the number of animals ovulating after mating, and the number of ova shed was lower than in the controls.…”

Place of Pheromone in Rape

“…Popularly known sex attractant is a pheromone. Its presence in mammals is well documented [13][14][15][16][17][18][19][20]. Attraction of a bull to a cow in estrous stage is the best example.…”

Pheromones in Human Urine: A Study

“…Male urine smell made female rat [21] and guinea pig [22] into estrogen stage. Sexual maturation was rapid in mice in female house, when exposed to male urine [23] and reverse when exposed to female urine [24,25].…”