A subset of beta-endorphin- or dynorphin-containing neurons in the medial basal hypothalamus accumulates estradiol.
We used the combined steroid autoradiography-immunocytochemical method to determine whether estradiol- or dexamethasone-concentrating cells contain endogenous opioid peptides. Ovariectomized-adrenalectomized female rats were given highly radioactive doses of 3H-estradiol or 3H-dexamethasone, then sacrificed to demonstrate nuclear steroid binding. Autoradiograms were prepared, exposed for 2-12 months, photodeveloped, and fixed; immunocytochemistry was carried out on the same sections using antibodies to beta-endorphin or dynorphin A (1-17). In the medial basal hypothalamus, many estradiol- and some dexamethasone-concentrating neurons were found intermingled with beta-endorphin or dynorphin-immunoreactive neurons. Of the beta-endorphin-immunoreactive neurons in the medial basal hypothalamus, 4% concentrated estradiol in their nuclei. In addition, a subset of beta-endorphin-immunoreactive cells in the anterior pituitary concentrated estradiol in their nuclei. Although none of the beta-endorphin-immunoreactive neurons in the medial basal hypothalamus concentrated dexamethasone in their nuclei, many of the beta-endorphin-immunoreactive cells in the anterior pituitary did. Of the dynorphin-immunoreactive neurons in the medial basal hypothalamus, 10% concentrated estradiol in their nuclei. These data are consistent with the hypothesis of a genomic effect of estradiol on a particular subset of medial basal hypothalamic neurons that produce endogenous opioid peptides.
Morrell
J I
JI
McGinty
J F
JF
Pfaff
D W
DW
D000315:Adrenalectomy; D000818:Animals; D001345:Autoradiography; D003907:Dexamethasone / Q000378:metabolism*; D004399:Dynorphins / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007033:Hypothalamus, Middle / Q000166:cytology / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D010052:Ovariectomy; D051381:Rats; D001615:beta-Endorphin
D004723:Endorphins; D004958:Estradiol; D001615:beta-Endorphin; D004399:Dynorphins; D003907:Dexamethasone