Progesterone receptors in hypothalamus and pituitary during the embryonic development of the chick: regulation by sex steroid hormones.
The distribution of progesterone receptor (PR) was immunohistochemically investigated in the hypothalamus and pituitary of the chick embryo (4-14 days of incubation) using an antibody against PR. PR first appears in the diencephalic floor on day 4 of incubation. From day 7 a distribution similar to that found in adult animals is observed. Between days 7 and 14, PR is detected in the periventricular and paraventricular regions, in the preoptic area and the organum vasculosum lamina terminalis. PR is not detectable in the pituitary at any stage studied. Estradiol and testosterone, but not dihydrotestosterone, increase the number of immunoreactive neurons in the hypothalamus from day 4 onwards and induce PR in the pituitary, from day 8 onwards. The early presence of PR in the brain, and its induction by estradiol in the anterior pituitary suggest a role for progesterone and estradiol in the ontogenic process of neuroendocrine regulation, very early during embryonic development.
Institut d'Embryologie du C.N.R.S. et du College de France, Nogent-sur-Marne.
R
R
Guennoun
M
M
Reyss-Brion
J M
JM
Gasc
D000818:Animals; D002642:Chick Embryo; D013196:Dihydrotestosterone / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007031:Hypothalamus / Q000032:analysis / Q000187:drug effects / Q000196:embryology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000032:analysis / Q000187:drug effects / Q000196:embryology*; D011980:Receptors, Progesterone / Q000032:analysis* / Q000187:drug effects / Q000276:immunology; D013739:Testosterone / Q000494:pharmacology*
D011980:Receptors, Progesterone; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol