Changes in Hypothalamic Luteinizing Hormone Releasing Factor (LHRF) in the Female Rat During Puberty
| Autor: | Charles H. Sawyer, V. Domingo Ramirez |
|---|---|
| Rok vydání: | 1966 |
| Předmět: |
Hypothalamo-Hypophyseal System
medicine.medical_specialty Pituitary gland medicine.drug_class Hypothalamus Gonadotropin-releasing hormone Biology chemistry.chemical_compound Endocrinology Estrus Pregnancy Internal medicine medicine Animals Estrous cycle Parallel study Estrogens Luteinizing Hormone Rats medicine.anatomical_structure chemistry Estrogen Estradiol benzoate Female Luteinizing hormone |
| Zdroj: | Endocrinology. 78:958-964 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/endo-78-5-958 |
| Popis: | In earlier work we found that the natural or estrogen-advanced onset of puberty in the female rat was accompanied by a sharp drop in pituitary LH and the appearance of LH in peripheral blood. The present investigation is a parallel study of puberal changes in hypothalamic LHRF. Acid extracts of stalk-median eminence of test animals were boiled to destroy LH and assayed for LHRF in immature rats primed with gonadotrophin after the manner of McCann and Ramirez. Shortly prior to the natural opening of the vagina, which occurs at about 38 days of age in Holtzman rats under our laboratory conditions, there was an abrupt rise in hypothalamic LHRF followed by an equally sharp drop to low LHRF values early on the first day of vaginal opening. The whole pattern could be advanced more than a week by daily treatment with low dosages of estrogen (estradiol benzoate 0.05 μg/day) starting at day 26. Under these conditions LHRF dropped to undetectable levels by the time the vagina opened (day 29–30) but recovered later ... |
| Databáze: | OpenAIRE |
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