Source:http://linkedlifedata.com/resource/pubmed/id/11831519
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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
2002-2-7
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pubmed:abstractText |
Seventeen seasonally anovulatory light horse mares were treated daily, starting January 5 (d 1), for 28 d with GnRH analog (GnRH-A; 50 ng/kg BW) and(or) thyrotropin-releasing hormone (TRH; 5 microg/kg BW) in a 2 x 2 factorial arrangement of treatments to test the hypothesis that combined treatment may stimulate follicular growth and development. Ovaries were examined via ultrasonography and jugular blood samples were collected every 3 d. Frequent blood samples were collected after treatment injections on d 1, 2, 4, 7, 11, 16, and 22; on d 29, all mares received an i.v. mixture of GnRH, TRH, sulpiride, and EP51389 (a growth hormone secretagogue) to assess pituitary responsiveness. No consistent effects (P > 0.1) of treatment were observed for plasma LH, FSH, prolactin, or thyroxine concentrations in samples collected every 3 d. The only effect on ovarian follicle numbers was a reduction in number of follicles 11 to 19 mm in diameter due to TRH treatment (P = 0.029). No mare ovulated during treatment. On the days of frequent sampling, mean LH (P = 0.0001) and FSH (P = 0.001) concentrations were higher in mares receiving GnRH-A and tended to increase from d 1 through 7. In contrast, mean prolactin (P = 0.001) and thyroid-stimulating hormone (P = 0.0001) concentrations were high in mares receiving TRH on d 1 but rapidly decreased thereafter. When mares were administered the secretagogue mixture on d 29, the LH response was greater (P = 0.0002) in mares that had previously received GnRH-A but the FSH response was not affected (P > 0.1); the prolactin response was greater (P = 0.014) and the TSH response was smaller (P = 0.0005) in mares that had previously received TRH. Surprisingly, an immediate growth hormone response to EP51389 was absent in all mares. In conclusion, daily GnRH-A treatment stimulated plasma LH and FSH concentrations immediately after injection; although no long-term elevation in preinjection concentrations was achieved, the responses gradually increased over time, indicating a stimulation of gonadotropin production and storage. Daily treatment with TRH stimulated plasma TSH and prolactin concentrations, but the response diminished rapidly and was minimal within a few days, indicating a depletion of pituitary stores and little or no stimulation of production. There was no beneficial effect of adding TRH treatment to the daily GnRH-A regimen.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Follicle Stimulating Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Gonadotropin-Releasing Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Luteinizing Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Prolactin,
http://linkedlifedata.com/resource/pubmed/chemical/Thyrotropin-Releasing Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Thyroxine
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0021-8812
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
80
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
208-13
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:11831519-Anestrus,
pubmed-meshheading:11831519-Animals,
pubmed-meshheading:11831519-Female,
pubmed-meshheading:11831519-Follicle Stimulating Hormone,
pubmed-meshheading:11831519-Gonadotropin-Releasing Hormone,
pubmed-meshheading:11831519-Horses,
pubmed-meshheading:11831519-Luteinizing Hormone,
pubmed-meshheading:11831519-Prolactin,
pubmed-meshheading:11831519-Random Allocation,
pubmed-meshheading:11831519-Seasons,
pubmed-meshheading:11831519-Thyrotropin-Releasing Hormone,
pubmed-meshheading:11831519-Thyroxine
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pubmed:year |
2002
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pubmed:articleTitle |
Responses of seasonally anovulatory mares to daily administration of thyrotropin-releasing hormone and(or) gonadotropin-releasing hormone analog.
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pubmed:affiliation |
Department of Animal Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803-4210, USA.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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