Thyrotropin releasing hormone interactions with growth hormone secretion in horses1
| Autor: | H. E. Pruett, L.R. Gentry, J. A. Cartmill, Donald L. Thompson, C.C. Williams |
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| Rok vydání: | 2003 |
| Předmět: |
endocrine system
medicine.medical_specialty endocrine system diseases Chemistry Thyroid Thyrotropin-releasing hormone Endogeny Stimulation General Medicine Prolactin Growth hormone secretion medicine.anatomical_structure Endocrinology Internal medicine Genetics medicine Animal Science and Zoology Sulpiride hormones hormone substitutes and hormone antagonists Food Science medicine.drug Hormone |
| Zdroj: | Journal of Animal Science. 81:2343-2351 |
| ISSN: | 1525-3163 0021-8812 |
| Popis: | Light horse mares, stallions, and geldings were used to 1) extend our observations on the thyrotropin releasing hormone (TRH) inhibition of GH secretion in response to physiologic stimuli and 2) test the hypothesis that stimulation of endogenous TRH would decrease the normal rate of GH secretion. In Exp. 1 and 2, pretreatment of mares with TRH (10 microg/kg BW) decreased (P 0.10) on GH concentrations. Similarly, 11 hourly injections of TRH administered to geldings in Exp. 5 did not alter (P > 0.10) GH concentrations either during the injections or for the next 14 h. In Exp. 5, it was noted that the prolactin and thyroid-stimulating hormone responses to TRH were great (P 0.10). In contrast, the GH response to aspartate and the prolactin response to sulpiride were greater (P < 0.05) in treated stallions than in controls. In summary, TRH inhibited exercise- and aspartate-induced GH secretion. The duration of the inhibition was at least 1 h but less than 2 h, and it waned with multiple injections. There is likely a TRH inhibition of endogenous GH episodes as well. Reduced thyroid feedback on the hypothalamic-pituitary axis did not alter basal GH and prolactin secretion. |
| Databáze: | OpenAIRE |
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