Pre- and posthatch developmental changes in hypothalamic thyrotropin-releasing hormone and somatostatin concentrations and in circulating growth hormone and thyrotropin levels in the chicken
| Autor: | Luc Berghman, Kris Geris, Veerle Darras, Eduard Kühn |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
endocrine system
medicine.medical_specialty animal structures endocrine system diseases Endocrinology Diabetes and Metabolism Fowl Hypothalamus Radioimmunoassay Thyrotropin-releasing hormone Thyrotropin Gestational Age Chick Embryo Biology Endocrinology Internal medicine medicine Animals Incubation Thyrotropin-Releasing Hormone Embryogenesis biology.organism_classification Somatostatin Growth Hormone embryonic structures Chickens hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | The Journal of endocrinology. 159(2) |
| ISSN: | 0022-0795 |
| Popis: | Thyrotropin-releasing hormone (TRH) and somatostatin (SRIH) concentrations were determined by RIA during both embryonic development and posthatch growth of the chicken. Both TRH and SRIH were already detectable in hypothalami of 14-day-old embryos (E14). Towards the end of incubation, hypothalamic TRH levels increased progressively, followed by a further increase in newly hatched fowl. SRIH concentrations remained stable from E14 to E17 and doubled between E17 and E18 to a concentration which was observed up to hatching. Plasma GH levels remained low during embryonic development, ending in a steep increase at hatching. Plasma TSH levels on the other hand decreased during the last week of the incubation. During growth, TRH concentrations further increased, whereas SRIH concentrations fell progressively towards those of adult animals. Plasma TSH levels increased threefold up to adulthood; the rise in plasma GH levels during growth was followed by a drop in adults. In conclusion, the present report shows that important changes occur in the hypothalamic TRH and SRIH concentration during both embryonic development and posthatch growth of the chicken. Since TRH and SRIH control GH and TSH release in the chicken, the hypothalamic data are compared with plasma GH and TSH fluctuations. |
| Databáze: | OpenAIRE |
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