EXTRACELLULAR CALCIUM DEPENDENCE OF THE NEUROTENSIN-INDUCED RELAXATION OF INTESTINAL SMOOTH MUSCLES - STUDIES WITH CALCIUM-CHANNEL BLOCKERS AND BAY K-8644

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dc.contributor.authorKULLAK, A
dc.contributor.authorDONOSO, MV
dc.contributor.authorHUIDOBROTORO, JP
dc.date.accessioned2025-01-23T19:25:51Z
dc.date.available2025-01-23T19:25:51Z
dc.date.issued1987
dc.description.abstractTo investigate whether the neurotensin-induced relaxation of the rat duodenum and ileum is dependent on the external concentration of calcium, the effect of the neuropeptide was studied in isolated intestinal segments superfused with Tyrode solution containing no calcium, 1 or 2.5 mM Ca2+. The neurotensin-induced intestinal relaxation was reduced when the extracellular calcium concentration was lowered. In addition, the inhibitory effect of neurotensin was cancelled when the tissues were incubated in the presence of diltiazem, methoxyverapamil or nifedipine. BAY K-8644, a structural analog of nifedipine that functions as an agonist of the calcium channel, potentiated the neurotensin-induced smooth muscle relaxation. The facilitatory effect of BAY K-8644 was antagonized by nifedipine, indicating competition between the 2 dihydropyridines. Apamin, the K+ channel blocker, antagonized the neurotensin-induced visceral relaxation, displacing the concentration-response curve of the peptide to the right. Furthermore, apamin also blocked the effect of neurotensin when the neuropeptide was assayed in the presence of BAY K-8644. It is concluded that the smooth muscle relaxation induced by neurotensin is dependent on external calcium, suggesting that the activation of the neuropeptide receptor causes an influx of calcium which leads to the opening of K+ channels before smooth muscle relaxation is triggered.
dc.fuente.origenWOS
dc.identifier.eissn1879-0712
dc.identifier.issn0014-2999
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/99534
dc.identifier.wosidWOS:A1987G920400003
dc.issue.numero3
dc.language.isoen
dc.pagina.final305
dc.pagina.inicio297
dc.revistaEuropean journal of pharmacology
dc.rightsacceso restringido
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleEXTRACELLULAR CALCIUM DEPENDENCE OF THE NEUROTENSIN-INDUCED RELAXATION OF INTESTINAL SMOOTH MUSCLES - STUDIES WITH CALCIUM-CHANNEL BLOCKERS AND BAY K-8644
dc.typeartículo
dc.volumen135
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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