Effects of Prolactin on Ovarian Plasmin Generation in the Process of Ovulation
| Autor: | N Koyama, Yukio Nakamura, Takahisa Oda, H. Yamada, Yasunori Yoshimura, Y. Ubukata, Motomu Ando, M Karube |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Ovulation
endocrine system medicine.medical_specialty medicine.drug_class Plasmin media_common.quotation_subject Alpha (ethology) Ovary Chorionic Gonadotropin Internal medicine medicine Animals Fibrinolysin media_common alpha-2-Antiplasmin Lagomorpha biology Cell Biology General Medicine biology.organism_classification Prolactin Kinetics Endocrinology medicine.anatomical_structure Reproductive Medicine Female Rabbits Gonadotropin Perfusion hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Biology of Reproduction. 46:322-327 |
| ISSN: | 1529-7268 0006-3363 |
| DOI: | 10.1095/biolreprod46.3.322 |
| Popis: | The present study was undertaken to assess the effects of prolactin (PRL) on gonadotropin-induced plasmin generation in the in vitro-perfused rabbit ovary. The ovarian plasmin activity was determined by measuring plasmin bound to its major inhibitor, alpha 2-plasmin inhibitor (alpha 2 PI-Plm). In the first experiment, exposure to hCG enhanced ovarian alpha 2 PI-Plm generation from 1.2 +/- 0.3 ng/min/ovary in unstimulated ovaries to 2.9 +/- 0.3 ng within 2 h. The concentration of alpha 2 PI-Plm reached a maximum at 4 h and then declined. A second peak occurred 8 h after hCG administration; however, the ovarian alpha 2 PI-Plm generation without hCG was very low throughout the entire perfusion period. In the subsequent experiment, the addition of PRL(10-10(3) ng/ml) to the perfusate inhibited hCG-induced ovulation in a dose-dependent manner. Exposure to PRL at 10(3) ng/ml significantly (p less than 0.05) inhibited hCG-induced alpha 2 PI-Plm generation in ovaries throughout the entire perfusion period. Furthermore, PRL inhibited hCG-stimulated alpha 2 PI-Plm generation at 4 h after hCG administration in the perfused rabbit ovaries in a dose-dependent manner. In conclusion, PRL directly inhibits hCG-induced ovulation in rabbit ovary, at least in part, by a mechanism depending upon inhibition of the plasmin-generating system in the preovulatory follicles. |
| Databáze: | OpenAIRE |
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