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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
18/07/2017 |
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Data da última atualização: |
18/07/2017 |
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Autoria: |
TANAKA, T.; MORI, Y.; HOSHINO, K. |
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Título: |
Long-term recording of hypothalamic gnrh pulse generator activity during programmed administration of progesterone and estradiol in the ovariectomized goat. |
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Ano de publicação: |
1994 |
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Fonte/Imprenta: |
Journal of Reproduction and Development, v. 40, n. 3, p. 183-188, Aug. 1994. |
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DOI: |
http://doi.org/10.1262/jrd.40.183 |
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Idioma: |
Inglês |
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Conteúdo: |
Changes in the GnRH pulse generator activity were examined during the programmed treatment with ovarian steroids, which mimicked endocrine events in the luteal and follicular phases, by recording the hypothalamic multiple unit activity specifically associated with the pulsa-tile LH secretion (MUA volleys) in ovariectomized goats. The steroidal milieu of the luteal phase was simulated by subcutaneously implanting silastic capsules containing progesterone and estra-diol, and that of follicular phase by intravenously infusing estradiol at a gradually increasing infusion-rate after removal of the progesterone capsules. The administration of progesterone alone for 3 days had little influence on MUA volleys, but there was a significant reduction (p<0.05) in the MUA volley frequency following the additional administration of estradiol, which resulted in the low pulse frequency observed in the normal luteal phase. In the mimicked follicular phase the MUA volley frequency was increased from 10.0± 2.9 to 13.7±1.9 volleys/12 h after the proges-terone removal, but then decreased gradually in parallel with an increase in the plasma estradiol concentration. There was no increase in MUA volley frequency during the transition from the basal to the surge mode of LH secretion. These results suggest that the hypothalamic GnRH pulse generator activity is suppressed during the luteal phase by a synergetic action of progesterone and estradiol, and that the acceleration of the GnRH pulse generator activity does not take place during the preovulatory LH surge in the female goat. MenosChanges in the GnRH pulse generator activity were examined during the programmed treatment with ovarian steroids, which mimicked endocrine events in the luteal and follicular phases, by recording the hypothalamic multiple unit activity specifically associated with the pulsa-tile LH secretion (MUA volleys) in ovariectomized goats. The steroidal milieu of the luteal phase was simulated by subcutaneously implanting silastic capsules containing progesterone and estra-diol, and that of follicular phase by intravenously infusing estradiol at a gradually increasing infusion-rate after removal of the progesterone capsules. The administration of progesterone alone for 3 days had little influence on MUA volleys, but there was a significant reduction (p<0.05) in the MUA volley frequency following the additional administration of estradiol, which resulted in the low pulse frequency observed in the normal luteal phase. In the mimicked follicular phase the MUA volley frequency was increased from 10.0± 2.9 to 13.7±1.9 volleys/12 h after the proges-terone removal, but then decreased gradually in parallel with an increase in the plasma estradiol concentration. There was no increase in MUA volley frequency during the transition from the basal to the surge mode of LH secretion. These results suggest that the hypothalamic GnRH pulse generator activity is suppressed during the luteal phase by a synergetic action of progesterone and estradiol, and that the acceleration of the GnRH pulse generator... Mostrar Tudo |
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Palavras-Chave: |
GnRH; MUA volley; Ovarian steroids; Pulse generator. |
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Thesagro: |
Estradiol. |
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Thesaurus Nal: |
Goats; Progesterone; Steroids. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02361naa a2200253 a 4500
001 2072852
005 2017-07-18
008 1994 bl uuuu u00u1 u #d
024 7 $ahttp://doi.org/10.1262/jrd.40.183$2DOI
100 1 $aTANAKA, T.
245 $aLong-term recording of hypothalamic gnrh pulse generator activity during programmed administration of progesterone and estradiol in the ovariectomized goat.
260 $c1994
520 $aChanges in the GnRH pulse generator activity were examined during the programmed treatment with ovarian steroids, which mimicked endocrine events in the luteal and follicular phases, by recording the hypothalamic multiple unit activity specifically associated with the pulsa-tile LH secretion (MUA volleys) in ovariectomized goats. The steroidal milieu of the luteal phase was simulated by subcutaneously implanting silastic capsules containing progesterone and estra-diol, and that of follicular phase by intravenously infusing estradiol at a gradually increasing infusion-rate after removal of the progesterone capsules. The administration of progesterone alone for 3 days had little influence on MUA volleys, but there was a significant reduction (p<0.05) in the MUA volley frequency following the additional administration of estradiol, which resulted in the low pulse frequency observed in the normal luteal phase. In the mimicked follicular phase the MUA volley frequency was increased from 10.0± 2.9 to 13.7±1.9 volleys/12 h after the proges-terone removal, but then decreased gradually in parallel with an increase in the plasma estradiol concentration. There was no increase in MUA volley frequency during the transition from the basal to the surge mode of LH secretion. These results suggest that the hypothalamic GnRH pulse generator activity is suppressed during the luteal phase by a synergetic action of progesterone and estradiol, and that the acceleration of the GnRH pulse generator activity does not take place during the preovulatory LH surge in the female goat.
650 $aGoats
650 $aProgesterone
650 $aSteroids
650 $aEstradiol
653 $aGnRH
653 $aMUA volley
653 $aOvarian steroids
653 $aPulse generator
700 1 $aMORI, Y.
700 1 $aHOSHINO, K.
773 $tJournal of Reproduction and Development$gv. 40, n. 3, p. 183-188, Aug. 1994.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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