Effect of hysterectomy on the short life-cycle corpus luteum produced after GnRH-induced ovulation in the anoestrous ewe
| Autor: | A. S. Law, J. A. Southee, William Haresign, Morag G. Hunter |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
endocrine system
Embryology medicine.medical_specialty medicine.medical_treatment Uterus Biology Luteal phase Hysterectomy Anestrus Endocrinology Estrus Ovulation Induction Pregnancy Induced ovulation Internal medicine medicine Animals Progesterone Sheep Obstetrics and Gynecology Cell Biology Short life medicine.anatomical_structure Reproductive Medicine In utero Corpus Luteum Maintenance Female Peak value Pituitary Hormone-Releasing Hormones Corpus luteum |
| Zdroj: | Reproduction. 84:149-155 |
| ISSN: | 1741-7899 1470-1626 |
| DOI: | 10.1530/jrf.0.0840149 |
| Popis: | Anoestrous Romney Marsh ewes were treated with small-dose (250 ng) multiple injections of GnRH. Ewes in Groups 1 and 3 were hysterectomized 2 weeks before treatment, while those in Groups 2 and 4 were intact controls. Groups 1 and 2 were primed with progesterone (+P) and treated with 2 h injections of GnRH (250 ng) for 36 h, while Groups 3 and 4 were not pretreated (-P) but were given 2 h injections of GnRH (250 ng) for 18 h. Both treatment regimens were terminated with a bolus injection of GnRH (125 micrograms), given to synchronize the timing of the LH surge and subsequent luteal progesterone production. The plasma progesterone profiles of 5/5 animals in Group 2 (+P controls) and 2/5 animals in Group 4 (-P controls) were indicative of normal luteal function, while the remaining 3/5 animals in Group 4 produced plasma progesterone profiles typical of abnormal luteal function. However, in all the hysterectomized animals (Groups 1 and 3) peripheral plasma progesterone concentrations rose to reach a mean peak value of 1.3 ng/ml plasma on Day 8 which was maintained in all animals irrespective of progesterone pretreatment. The absence of a fall in progesterone concentrations precluded the identification of any animal in Group 4 showing abnormal luteal function. It was also noted that, after hysterectomy, although the corpus luteum was maintained, it was with reduced secretory capacity. The prevention of the expected proportion (70%) of -P animals from displaying a decline in plasma progesterone concentration after hysterectomy provides firm evidence that the uterus is involved in the premature regression of the short-cycle corpus luteum. |
| Databáze: | OpenAIRE |
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