| Title: | Effects of exposure to male goat hair extracts on luteinizing hormone secretion and neuronal activation in seasonally anestrous ewes |
| Author(s): | Ohara H; Mogi K; Ichimaru T; Ohkura S; Takeuchi Y; Mori Y; Okamura H; |
| Address: | "Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan" |
| ISSN/ISBN: | 1347-7439 (Electronic) 0916-7250 (Print) 0916-7250 (Linking) |
| Abstract: | "In sheep and goats, exposure of seasonally anestrous females to males or their fleece/hair activates the gonadotropin-releasing hormone (GnRH) pulse generator leading to pulsatile luteinizing hormone (LH) secretion. Pheromones emitted by sexually mature males are thought to play a prominent role in this male effect. In the present study, we first aimed to clarify whether the male goat pheromone is effective in ewes. Seasonally anestrous St. Croix ewes were exposed to hair extracts derived from either intact or castrated (control) male Shiba goats. The male goat-hair extract significantly increased LH secretion compared to the control, suggesting that an interspecies action of the male pheromone occurs between sheep and goats. Using the male goat-hair extract as the pheromone source, we then aimed to clarify the neural pathway involved in the signal transduction of the male pheromone. Ewes were exposed to either the goat-hair extract or the control and sacrificed 2 hr after the exposure. Expression of c-Fos, a marker of neuronal activation, was immunohistochemically examined. The male goat-hair extract significantly increased the c-Fos expression compared to the control in regions of the vomeronasal system, such as the accessory olfactory bulb and medial amygdala, and the arcuate nucleus. The main olfactory bulb did not exhibit any significant increase in the c-Fos expression by the male goat-hair extract. This result suggests that the neural signal of the male pheromone is conveyed to the GnRH pulse generator through the activated regions in ewes" |
| Keywords: | "Anestrus/*physiology Animals Female Gene Expression Regulation/drug effects Genes, fos/physiology Goats/*physiology Hair/*chemistry Luteinizing Hormone/*metabolism Male Neurons Seasons Sheep/*physiology Species Specificity;" |
| Notes: | "MedlineOhara, Hiromi Mogi, Kazutaka Ichimaru, Toru Ohkura, Satoshi Takeuchi, Yukari Mori, Yuji Okamura, Hiroaki eng Research Support, Non-U.S. Gov't Japan 2014/06/20 J Vet Med Sci. 2014 Oct; 76(10):1329-37. doi: 10.1292/jvms.14-0260. Epub 2014 Jun 19" |
