Estrogen induces ultrastructural changes in progesterone receptor-containing GABA neurons of the primate hypothalamus.
Estrogen affects gonadotrophin levels and sex behavior in monkeys. This action could be via inhibitory GABA-ergic neurons in the hypothalamus. We tested for direct estrogen actions on such neurons. Seven days after ovariectomy (OVX) or OVX + estrogen treatment (10 mg estradiol valerate in 1 ml sesame oil s.c. on the day of OVX), light- and electron-microscopic double immunostaining procedures were used for simultaneous visualization of immunoreactivity for progesterone receptors (PR) and glutamic acid decarboxylase (GAD), and to detect ultrastructural changes in PR-containing neurons in the arcuate and ventromedial hypothalamic nuclei of colchicine- and noncolchicine-treated African green monkeys (Cercopithecus aethiops). Immunoreactivity for PR was found only in cell nuclei, and estrogen treatment enhanced the intensity of the immunostaining: in estrogen-treated monkeys in the arcuate nucleus 62%, while in the ventromedial nucleus 42% of the neurons contained PR-immunoreactive nuclei. All of the PR-containing neurons were immunopositive for GAD in colchicine-pretreated monkeys. OVX induced whorl body formation, while estrogen treatment of OVX animals resulted in a large number of nematosomes. While all of the whorl bodies and the majority of nematosomes were observed in PR-immunopositive GAD neurons, nematosomes were also found in non-PR-containing GAD-immunoreactive cells.
Leranth
C
C
Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Conn.
Shanabrough
M
M
Naftolin
F
F
D000818:Animals; D002522:Chlorocebus aethiops; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D007031:Hypothalamus / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D007158:Immunologic Techniques; D008854:Microscopy, Electron; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010052:Ovariectomy; D011980:Receptors, Progesterone / Q000378:metabolism*; D013194:Staining and Labeling; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D004967:Estrogens; D011980:Receptors, Progesterone; D004958:Estradiol; D005680:gamma-Aminobutyric Acid