Vasodilator Actions of Urocortin and Related Peptides in the Human Perfused Placenta in Vitro1
| Autor: | Chiara Botti, Ian M. Leitch, Roger Smith, A.L.A. Boura, William A. W. Walters, M.A. Read |
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| Rok vydání: | 1998 |
| Předmět: |
Urocortin
endocrine system medicine.medical_specialty Fetus business.industry Endocrinology Diabetes and Metabolism Biochemistry (medical) Clinical Biochemistry Vasodilation Adrenocorticotropic hormone Biochemistry Endocrinology medicine.anatomical_structure Internal medicine Placenta medicine medicine.symptom Receptor business Perfusion hormones hormone substitutes and hormone antagonists Vasoconstriction |
| Zdroj: | The Journal of Clinical Endocrinology & Metabolism. 83:4510-4513 |
| ISSN: | 1945-7197 0021-972X |
| Popis: | Urocortin, is a recently isolated peptide belonging to the CRH family that binds with high affinity to the CRH2 receptor. Like CRH, urocortin causes hypotension in the rat, but its vasoactive actions have not yet been studied in the human. We have compared the vasoactive properties of urocortin, CRH, and urotensin-1 in the human fetal placental vasculature in vitro. Single placental lobules were bilaterally perfused (maternal and fetal sides, 5 mL/min each; 95% O2-5% CO2; 37 C), and changes in fetal arterial perfusion pressure were recorded. Submaximal vasoconstriction was induced by PGF2α (4 ± 0.7μ mol/L), which increased perfusion pressure from 19.6 ± 1.4 to 100.7 ± 3.1 mm Hg (n = 38; P < 0.001). Subsequent fetal arterial infusion of urocortin (0.001–1 nmol/L) caused concentration-dependent vasodilatation. Urocortin was equipotent with urotensin-1 and 25 times more potent than CRH in causing vasodilatation. Nevertheless, the maximum vasodilator responses to each of the peptides were similar (P > 0.05). The CRH receptor antagonist, α-helical CRH-(9–41) (0.2 nmol/L) significantly attenuated the vasodilatation produced by urocortin, urotensin-1, and CRH (P < 0.05). These results indicate a possible physiological role for urocortin in the modulation of human fetal placental vascular tone by activation of CRH2-like receptors. |
| Databáze: | OpenAIRE |
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