title: The modes of the anterior hypothalamic area as the regulatory center for the gonadotropin release.
abstract: The effects of the anterior hypothalamic area (AHA) implants of gonadal steroid estrogen and progesterone as well as the effects of electrical stimulation and electrolytic lesion confined in this area on the gonadotropin secretion were investigated in ovariectomized estradiol (20 microgram sc)-primed adult Wistar rats housed in light and temperature controlled room. Progesterone implants evoked the rise of serum LH by 6 hr whereas estradiol implants suppressed serum FSH by 24 hr after implantation. Electrical stimulation effectively depleted both gonadotropins with a latency not shorter than 6 hr. The lesion significantly prevented FSH elevation investigated at 72 hr post ovariectomy and potentiated FSH secretion in response to estradiol treatment at 3 week post ovariectomy. The result revealed the involvment of the AHA in LH release mechanism which required progesterone activation while its involvement in FSH regulatory mechanism depended upon estrogen. The area was elucidated as the inhibitory as well as the stimulatory loci for the feedback action of estrogen on FSH release.
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D004572:Electrolysis; D004967:Estrogens / Q000502:physiology; D005246:Feedback; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006062:Gonadotropins / Q000378:metabolism*; D007031:Hypothalamus / Q000502:physiology*; D007032:Hypothalamus, Anterior / Q000502:physiology*; D007986:Luteinizing Hormone / Q000378:metabolism; D011374:Progesterone / Q000502:physiology; D051381:Rats
chemical_list: D004967:Estrogens; D006062:Gonadotropins; D011374:Progesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone