2012 Fiscal Year Final Research Report

A mechanism underlying the dioxin-produced sexual immaturity: an imprinting of the lowered expression of gonadotropin-releasing hormone

Research Project

Project/Area Number	23790152
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Environmental pharmacy
Research Institution	Kyushu University
Principal Investigator	TAKEDA Tomoki 九州大学, 薬学研究院, 助教 (60596831)
Project Period (FY)	2011 – 2012
Keywords	環境化学
Research Abstract	This study suggests the novel mechanism that maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) fixes the status of a reduction in the hypothalamic expression of gonadotropin-releasing hormone (GnRH)in the offspring by reducing perinatal steroidogenesis, and this is the origin for imprinted defects in sexual behaviors at adulthood. The results obtained in this study were as follows: 1) Areduction in GnRH mRNA by TCDD emerges from postnatal day 4 to adulthood. 2) Intracerebroventricular infusion of GnRH into the TCDD-exposed pups after their growing up restored many defects in sexual behaviors. And 3) Direct supplementation of gonadotropininto TCDD-exposed fetuses at GD17 rescueda TCDD-produced attenuation of hypothalamic GnRH mRNA in the male pups.

(5 results)