Properties and regulation of high-affinity pituitary receptors for corticotropin-releasing factor
| Autor: | Peter C. Wynn, Greti Aguilera, John L. Morell, Kevin J. Catt |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Chemical Phenomena Corticotropin-Releasing Hormone Biophysics Receptors Cell Surface Peptide Adrenocorticotropic hormone In Vitro Techniques Receptors Corticotropin-Releasing Hormone Biochemistry Iodine Radioisotopes chemistry.chemical_compound Adrenocorticotropic Hormone Anterior pituitary Pituitary Gland Anterior Internal medicine medicine Animals Secretion Receptor Molecular Biology chemistry.chemical_classification Adrenalectomy Rats Inbred Strains Cell Biology Rats Dissociation constant Chemistry EGTA medicine.anatomical_structure Endocrinology chemistry hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | Biochemical and Biophysical Research Communications. 110:602-608 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/0006-291x(83)91192-0 |
| Popis: | Specific receptors for corticotropin-releasing factor (CRF) were identified in the rat anterior pituitary gland by binding studies with 125I-Tyr-CRF. Binding of the labeled CRF analog to pituitary particles was rapid and temperature-dependent, and reached steady state within 45 min at 22°C. The CRF binding sites were saturable and of high affinity, with dissociation constant (Kd) of 0.76 × 10−9 M. Pituitary binding of 125I-Tyr-CRF was inhibited by CRF, Tyr-CRF and the active 15–41 fragment of CRF, but not by the inactive 21–41 CRF fragment and unrelated peptides. The binding-inhibition potencies of the CRF peptides were similar to their activities as stimuli of adrenocorticotropic hormone (ACTH) release. The high-affinity CRF sites were markedly reduced in adrenalectomized rats, and this change was reversed by dexamethasone treatment. These data indicate that the high-affinity CRF sites demonstrated in the anterior pituitary are the functional receptors which mediate the stimulatory action of the peptide on ACTH release, and that CRF receptors are down-regulated during increased secretion of the hypothalamic hormone. |
| Databáze: | OpenAIRE |
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