Hormonal regulation of oxytocin-induced prostaglandin F2α secretion by the bovine and ovine uterus in vivo
| Autor: | George E Mann, J. H. Payne, G.E. Lamming |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
medicine.medical_specialty
Ovariectomy Uterus Prostaglandin Dinoprost Oxytocin chemistry.chemical_compound Endocrinology Food Animals Downregulation and upregulation Internal medicine medicine Animals Receptor Progesterone Sheep Estradiol Oxytocin receptor Hormones Kinetics medicine.anatomical_structure chemistry Receptors Oxytocin Ovariectomized rat Cattle Female Animal Science and Zoology hormones hormone substitutes and hormone antagonists medicine.drug Hormone |
| Zdroj: | Domestic Animal Endocrinology. 21:127-141 |
| ISSN: | 0739-7240 |
| Popis: | In long-term ovariectomized ewes and cows, endometrial oxytocin receptors rest at relatively high levels but oxytocin is unable to induce prostaglandin F 2α release. A series of studies were carried out to investigate the roles of physiological levels of progesterone and estradiol in "activating" these receptors in terms of permitting oxytocin-induced prostaglandin F 2α release. In long-term ovariectomized cows, treatment with progesterone, but not estradiol, resulted in the induction of responsiveness to oxytocin. This responsiveness appeared within 2 d of progesterone treatment, reached a maximum by 6 d and was maintained to Day 18. In ovariectomized ewes, while estradiol treatment did induce temporary responsiveness to oxytocin after 3 d of treatment, treatment with progesterone was required to induce sustained responsiveness that appeared by Day 9 of treatment and was maintained to Day 12. Measurement of endometrial receptors for oxytocin revealed a significant decline in oxytocin receptors by Day 6 of progesterone treatment when responsiveness to oxytocin was maximal, demonstrating that receptor concentrations were not a limiting factor. The most likely mechanism by which progesterone treatment induces responsiveness to oxytocin may be through the up regulation of post receptor signaling pathways and/or enzymes involved in prostaglandin synthesis. |
| Databáze: | OpenAIRE |
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