[Hypothalamo-hypophyseal correlates in the chick embryo: thyrotropic activity of adenohypophyseal grafts from donor embryos of various ages. Effect or pretreatment with TRH]

Abstract

Adenohypophyses from 10 to 18-day-old chick embryonic donors grafted in 3 days chick embryos, thus disconnected from the hypothalamus, had a partially autonomous thyrotrophic activity. However this functional autonomy was greater in grafts from donors aged 10 or 11 days than from older embryos or from 11-day donors pretreated with T.R.H. before grafting. This strongly suggests that hypothalamo-adenohypophysis-thyroidal relationship establish normally between 11 and 12 days of embryonic life.