Effects of histamine and related compounds on thyrotropin secretion in rats
| Autor: | Terunori Mitsuma, Tsuyoshi Nogimori, Masahiro Chaya, De Heng Sun |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Male
endocrine system medicine.medical_specialty endocrine system diseases Endocrinology Diabetes and Metabolism Thyrotropin-releasing hormone Thyrotropin Histamine H1 receptor Peptide hormone chemistry.chemical_compound Endocrinology Histamine H2 receptor Internal medicine medicine Animals Secretion Histidine Thyrotropin-Releasing Hormone Pyrilamine Dose-Response Relationship Drug Rats Inbred Strains Famotidine Rats Thiazoles chemistry hormones hormone substitutes and hormone antagonists Histamine Hormone |
| Zdroj: | Hormone research. 23(2) |
| ISSN: | 0301-0163 |
| Popis: | The effects of histamine (HA) and related compounds on thyrotropin-releasing hormone (TRH) and thyrotropin (TSH) secretion in rats were studied. Histidine (1.0 g/kg), HA (5.0 mg/kg) or histamine antagonists mepyramine (MP) (100 mg/kg) or famotidine (FA) (5.0 mg/kg) were injected intraperitoneally, and the rats were decapitated at various intervals after the injection. The hypothalamic immunoreactive TRH (ir-TRH) content increased significantly after histidine or HA injection, decreased significantly after FA injection, but was not changed by MP. The plasma ir-TRH concentration did not change significantly after injection of these drugs. The plasma TSH levels decreased significantly in a dose-related manner after histidine or HA injection and increased significantly in a dose-related manner after FA injection. The plasma thyroid hormone levels showed no changes. In the FA-pretreated group, the inhibitory effect of histidine or HA on TSH levels was prevented, but not in the MP-pretreated group. The plasma ir-TRH and TSH responses to cold were inhibited by histidine or HA and enhanced by FA. The plasma TSH response to TRH was inhibited by histidine or HA and enhanced by FA. The inactivation of TRH immunoreactivity by hypothalamus or plasma in vitro after histidine, HA, MP or FA was not different from that of the control. These findings suggest that histamine may act both on the hypothalamus and the pituitary to inhibit TRH and TSH release, and that its effects may be mediated via H2-receptor. |
| Databáze: | OpenAIRE |
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