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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
25/03/1997 |
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Data da última atualização: |
11/07/2023 |
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Autoria: |
NANCARROW, C. D.; WALLACE, A. L. C.; GREWAL, A. S. |
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Título: |
The early pregnancy factor of sheep and cattle. |
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Ano de publicação: |
1981 |
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Fonte/Imprenta: |
Journal of reproduction and fertility. Supplement, v. 30, p. 191-199, 1981. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: The appearance and production of an early pregnancy factor (EPF) has been studied in sheep and cattle. This factor can be detected in serum and tissues of pregnant animals by its synergistic action with antilymphocyte serum in reducing the number of rosettes formed in a rosette inhibition test. The range of the rosette inhibition titre for serum from non-pregnant animals was 4–10. Values higher than these were considered to indicate the presence of EPF. In one ewe EPF was detected 29.5 h after the onset of oestrus at which time a zygote was recovered. The transfer of sheep zygotes into unmated non-pregnant ewes, and the infusion of extracts of mouse zygotes into the oviducts ipsilateral to the side of ovulation in ewes caused an increase in the titre of serum from the recipient animals. Infusion of extracts of unfertilized mouse ova did not change the titre. Removal of zygotes or embryos resulted in a reduction in the titre within 48 h to non-pregnant values. Extracts of tissues analysed for the presence of EPF gave high titres when taken from early pregnant ewes whereas tissues from non-pregnant animals gave low values. Removal of the ovary containing the corpus luteum from sheep 4–5 days after mating and in which pregnancy was maintained by exogenous progesterone resulted in a decrease in titre during the following 2–4 days. Removal of the contralateral ovary or the induction of luteolysis with a prostaglandin F-2α analogue did not result in a decrease. In cattle, pregnancy diagnosis by the rosette inhibition test 4 days after an artificial breeding programme gave good agreement with conventional pregnancy testing methods, e.g. palpation per rectum and plasma progesterone assays. From these experiments we suggest that a substance ‘zygotin’ is released by the fertilized egg and stimulates the production of EPF, most probably from the ovary containing the corpus luteum. Zygotin may act directly on the ovary or via an intermediary substance released by the oviduct. The role of EPF is unknown. It does not appear to be necessary for the maintenance of pregnancy because ovariectomized sheep with no demonstrable EPF remain pregnant when given exogenous progesterone. Routine pregnancy testing in sheep and cattle is not practicable with the present rosette inhibition test. MenosAbstract: The appearance and production of an early pregnancy factor (EPF) has been studied in sheep and cattle. This factor can be detected in serum and tissues of pregnant animals by its synergistic action with antilymphocyte serum in reducing the number of rosettes formed in a rosette inhibition test. The range of the rosette inhibition titre for serum from non-pregnant animals was 4–10. Values higher than these were considered to indicate the presence of EPF. In one ewe EPF was detected 29.5 h after the onset of oestrus at which time a zygote was recovered. The transfer of sheep zygotes into unmated non-pregnant ewes, and the infusion of extracts of mouse zygotes into the oviducts ipsilateral to the side of ovulation in ewes caused an increase in the titre of serum from the recipient animals. Infusion of extracts of unfertilized mouse ova did not change the titre. Removal of zygotes or embryos resulted in a reduction in the titre within 48 h to non-pregnant values. Extracts of tissues analysed for the presence of EPF gave high titres when taken from early pregnant ewes whereas tissues from non-pregnant animals gave low values. Removal of the ovary containing the corpus luteum from sheep 4–5 days after mating and in which pregnancy was maintained by exogenous progesterone resulted in a decrease in titre during the following 2–4 days. Removal of the contralateral ovary or the induction of luteolysis with a prostaglandin F-2α analogue did not result in a decrease. In cattle... Mostrar Tudo |
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Palavras-Chave: |
Drug effects; Gestacao; Hormonios; Ovary; Placentacao; Suppressor Factors. |
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Thesagro: |
Ovino. |
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Thesaurus Nal: |
Castration; Cattle; Cloprostenol; Embryo transfer; Females; Fertilization (reproduction); Immunologic factors; Pharmacology; Physiology; Pregnancy; Reproduction; Sheep. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 03299naa a2200373 a 4500
001 1522252
005 2023-07-11
008 1981 bl uuuu u00u1 u #d
100 1 $aNANCARROW, C. D.
245 $aThe early pregnancy factor of sheep and cattle.$h[electronic resource]
260 $c1981
520 $aAbstract: The appearance and production of an early pregnancy factor (EPF) has been studied in sheep and cattle. This factor can be detected in serum and tissues of pregnant animals by its synergistic action with antilymphocyte serum in reducing the number of rosettes formed in a rosette inhibition test. The range of the rosette inhibition titre for serum from non-pregnant animals was 4–10. Values higher than these were considered to indicate the presence of EPF. In one ewe EPF was detected 29.5 h after the onset of oestrus at which time a zygote was recovered. The transfer of sheep zygotes into unmated non-pregnant ewes, and the infusion of extracts of mouse zygotes into the oviducts ipsilateral to the side of ovulation in ewes caused an increase in the titre of serum from the recipient animals. Infusion of extracts of unfertilized mouse ova did not change the titre. Removal of zygotes or embryos resulted in a reduction in the titre within 48 h to non-pregnant values. Extracts of tissues analysed for the presence of EPF gave high titres when taken from early pregnant ewes whereas tissues from non-pregnant animals gave low values. Removal of the ovary containing the corpus luteum from sheep 4–5 days after mating and in which pregnancy was maintained by exogenous progesterone resulted in a decrease in titre during the following 2–4 days. Removal of the contralateral ovary or the induction of luteolysis with a prostaglandin F-2α analogue did not result in a decrease. In cattle, pregnancy diagnosis by the rosette inhibition test 4 days after an artificial breeding programme gave good agreement with conventional pregnancy testing methods, e.g. palpation per rectum and plasma progesterone assays. From these experiments we suggest that a substance ‘zygotin’ is released by the fertilized egg and stimulates the production of EPF, most probably from the ovary containing the corpus luteum. Zygotin may act directly on the ovary or via an intermediary substance released by the oviduct. The role of EPF is unknown. It does not appear to be necessary for the maintenance of pregnancy because ovariectomized sheep with no demonstrable EPF remain pregnant when given exogenous progesterone. Routine pregnancy testing in sheep and cattle is not practicable with the present rosette inhibition test.
650 $aCastration
650 $aCattle
650 $aCloprostenol
650 $aEmbryo transfer
650 $aFemales
650 $aFertilization (reproduction)
650 $aImmunologic factors
650 $aPharmacology
650 $aPhysiology
650 $aPregnancy
650 $aReproduction
650 $aSheep
650 $aOvino
653 $aDrug effects
653 $aGestacao
653 $aHormonios
653 $aOvary
653 $aPlacentacao
653 $aSuppressor Factors
700 1 $aWALLACE, A. L. C.
700 1 $aGREWAL, A. S.
773 $tJournal of reproduction and fertility. Supplement$gv. 30, p. 191-199, 1981.
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| 1. |  | SANTANA, G. P.; PINHEIRO, L. M. de M.; GOULART, A. T.; JESUS FILHO, M. F. de; FABRIS, J. D.; SANTANA, D. P. Transformação da litologia de esteatito (pedra-sabão). In: CONGRESSO BRASILEIRO DE CIÊNCIA DO SOLO, 25., 1995, Viçosa, MG. O solo nos grandes domínios morfoclimáticos do Brasil e o desenvolvimento sustentado: resumos expandidos. Viçosa, MG: Sociedade Brasileira de Ciência do Solo: Universidade Federal de Viçosa, 1995. p. 247-249.| Tipo: Resumo em Anais de Congresso |
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