Thyroid Hormone Replacement Restores Circulating Enkephalin Concentrations in Hypophysectomized Fetal Sheep
| Autor: | I. Ross Young, I. Caroline McMillen, Giuseppe Simonetta |
|---|---|
| Přispěvatelé: | Young, I Ross |
| Rok vydání: | 2002 |
| Předmět: |
endocrine system
medicine.medical_specialty Hypophysectomy Epinephrine Enkephalin Enkephalin Methionine medicine.medical_treatment Hormone replacement Sheep fetus Gestational Age Biochemistry Norepinephrine Cellular and Molecular Neuroscience Fetus Pregnancy Internal medicine medicine Animals Infusions Intravenous Saline Sheep Chemistry Thyroid Fetal Blood Thyroxine Endocrinology medicine.anatomical_structure Gestation Female |
| Zdroj: | Journal of Neurochemistry. 63:1386-1391 |
| ISSN: | 0022-3042 |
| DOI: | 10.1046/j.1471-4159.1994.63041386.x |
| Popis: | We have investigated the effects of fetal hypophysectomy (HX) with or without thyroxine (T4)replacement on the plasma concentrations of free methionine-enkephalin (free Met-Enk), noradrenaline, and adrenaline in late gestation sheep fetus. Plasma adrenaline concentrations were significantly higher in intact fetal sheep (1.05 +/- 0.12 pmol/L) between 125 and 140 days of gestation when compared with the HX + saline (0.64 +/- 0.10 pmol/L) and HX + T4 (0.61 +/- 0.08 pmol/L) groups. During the first 15 days of the T4 or saline infusion, the plasma concentrations of free Met-Enk were significantly higher in the HX + T4 group (392 +/- 40 pmol/L) than in the HX + saline group (299 +/- 43 pmol/L). At this stage of gestation, however, circulating concentrations of free Met-Enk were significantly higher in intact fetal sheep (556 +/- 51 pmol/L) than in either of the HX groups. Between 125 and 140 days of gestation, plasma free Met-Enk concentrations were similar and significantly higher in the intact and HX + T4 groups than those measured in the HX + saline fetal sheep. We conclude that the decrease in circulating free Met-Enk concentrations after removal of the fetal pituitary is primarily a consequence of functional athyroidism. |
| Databáze: | OpenAIRE |
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