Abstract: 69

DEVELOPMENTAL INCREASE IN THE EXPRESSION OF GONADOTROPIN-RELEASING HORMONE-II (GnRH-II) IN THE PRIMATE HYPOTHALAMUS.

Valerie Latimer¹ , Vasilios Garyfallou¹ , Steve Kohama¹ , Henryk Urbanski¹
Division of Neuroscience, Oregon Regional Primate Research Center, Beaverton, OR. ¹

It has recently been shown that a second form of gonadotropin-releasing hormone (GnRH-II) exists in the primate brain and is capable of stimulating luteinizing hormone release. However, little is known about the distribution of GnRH-II mRNA and the control of its expression during developmental events, such as puberty. Therefore, the aim of this study was to examine GnRH-II mRNA in the hypothalami of pre-pubertal (7 months) and adult (10 - 15 years) male and female rhesus macaques (Macaca mulatta, n=3/group). Eight hypothalamic sections (25 µm) per animal were processed for in situ hybridization using a ³⁵S-labeled, anti-sense, GnRH-II riboprobe. The pre-pubertal animals showed a high level of expression of GnRH-II mRNA in the supraoptic and paraventricular nuclei, and to a lesser extent in the suprachiasmatic nucleus. The adults showed a similar mRNA distribution pattern, but also expressed GnRH-II in the medial basal hypothalamus (MBH). These results imply that the MBH upregulates GnRH-II expression during development and may represent a mechanism that controls the onset of puberty in primates. Grant Support: NIH HD-29186 and RR-00163

    This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.