Estradiol Acts Locally Within the Retrochiasmatic Area to Inhibit Pulsatile Luteinizing-Hormone Release in the Female Sheep during Anestrus1
| Autor: | Jean-Claude Thiéry, Bernadette Delaleu, J Gallegos-Sanchez, Alain Caraty, Benoît Malpaux |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Estrous cycle
medicine.medical_specialty medicine.drug_class Dopaminergic Pulsatile flow Area under the curve Cell Biology General Medicine Biology Endocrinology Reproductive Medicine Hypothalamus Estrogen Internal medicine medicine Gonadotropin Luteinizing hormone hormones hormone substitutes and hormone antagonists |
| Zdroj: | Biology of Reproduction. 56:1544-1549 |
| ISSN: | 1529-7268 0006-3363 |
| DOI: | 10.1095/biolreprod56.6.1544 |
| Popis: | In the present study we have identified a site of action of estradiol in the inhibition of LH secretion during anestrus in the ewe. In the first experiment, we studied six sites: the medial preoptic area, the lateral preoptic area, the ventromedial hypothalamus, the ventrolateral hypothalamus, the retrochiasmatic area (RCh), and the periventricular posterior hypothalamus. We compared the changes in parameters of pulsatile LH secretion (interpulse interval, mean nadir, mean amplitude, and mean area under curve) during three 6-h sampling periods: before and 30-36 h and 9 days after intracerebral implantation of crystalline estradiol. Animals that received estradiol in the RCh (n = 5) showed a significantly greater increase in both the intervals between pulses of LH (up 116%, p < 0.03) and the area under the curve (up 180%, p < 0.01) than any of the other groups of 7 animals. In the second experiment, implantation of estradiol in the RCh (n = 6) induced an increase in the intervals between pulses of LH (p < 0.03), whereas receiving an empty implant (n = 6) had no effect, showing that estradiol specifically induced increases in the intervals between pulses. Thus, estradiol appears to act in the RCh where the dopaminergic A15 nucleus, known to inhibit pulsatile LH release, is located. |
| Databáze: | OpenAIRE |
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