Differential Antagonist Activity of α -Helical Corticotropin-Releasing Factor 9–41 in Three Bioassay Systems *
1991; Oxford University Press; Volume: 129; Issue: 3 Linguagem: Inglês
10.1210/endo-129-3-1312
ISSN1945-7170
AutoresLaurel A. Fisher, Catherine Rivier, Jean Rivier, Marvin Brown,
Tópico(s)Pituitary Gland Disorders and Treatments
ResumoStudies were performed in conscious unrestrained rats to compare the ability of the CRF receptor antagonist, α-helical CRF9–41, to inhibit the actions of CRF in three in vivo bioassay systems. When both peptides were administered intracerebroventricularly, an antagonist:agonist ratio between 6:1–12:1 was required to abolish CRF-induced elevations of plasma catecholamine levels. When both peptides were administered iv, CRF-induced hypotension and tachycardia were completely prevented by an antagonist:agonist ratio of 6:1, whereas total blockade of CRF-induced elevations of plasma ACTH and β-endorphin levels required an antagonist:agonist ratio of 3000:1. These results demonstrate marked differences in the ability of α-helical CRF9–41 to antagonize various biological actions of CRF and support the existence of multiple CRF receptor subtypes. (Endocrinology129: 1312–1316, 1991)
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