Serotonin receptor-mediated vasorelaxation occurs primarily through 5-HT 4 activation in bovine lateral saphenous vein.

Autor: Trotta RJ; Department of Animal and Food Sciences, University of Kentucky, Lexington, Kentucky, USA., Harmon DL; Department of Animal and Food Sciences, University of Kentucky, Lexington, Kentucky, USA., Klotz JL; Forage-Animal Production Research Unit, USDA-ARS, Lexington, Kentucky, USA.
Jazyk: angličtina
Zdroj: Physiological reports [Physiol Rep] 2024 Jul; Vol. 12 (13), pp. e16128.
DOI: 10.14814/phy2.16128
Abstrakt: To better understand mechanisms of serotonin- (5-HT) mediated vasorelaxation, isolated lateral saphenous veins from cattle were assessed for vasoactivity using myography in response to increasing concentrations of 5-HT or selective 5-HT receptor agonists. Vessels were pre-contracted with 1 × 10 -4  M phenylephrine and exposed to increasing concentrations of 5-HT or 5-HT receptor agonists that were selective for 5-HT 1B , 5-HT 2B , 5-HT 4 , and 5-HT 7 . Vasoactive response data were normalized as a percentage of the maximum contractile response induced by the phenylephrine pre-contraction. At 1 × 10 -7  M 5-HT, a relaxation was observed with an 88.7% decrease (p < 0.01) from the phenylephrine maximum. At 1 × 10 -4  M 5-HT, a contraction was observed with a 165% increase (p < 0.01) from the phenylephrine maximum. Increasing concentrations of agonists selective for 5-HT 2B , 5-HT 4 , or 5-HT 7 resulted in a 27%, 92%, or 44% (p < 0.01) decrease from the phenylephrine maximum, respectively. Of these 5-HT receptor agonists, the selective 5-HT 4 receptor agonist resulted in the greatest potency (-log EC 50 ) value (6.30) compared with 5-HT 2B and 5-HT 7 receptor agonists (4.21 and 4.66, respectively). To confirm the involvement of 5-HT 4 in 5-HT-mediated vasorelaxation, blood vessels were exposed to either DMSO (solvent control) or a selective 5-HT 4 antagonist (1 × 10 -5  M) for 5-min prior to the phenylephrine pre-contraction and 5-HT additions. Antagonism of the 5-HT 4 receptor attenuated the vasorelaxation caused by 5-HT. Approximately 94% of the vasorelaxation occurring in response to 5-HT could be accounted for through 5-HT 4 , providing strong evidence that 5-HT-mediated vasorelaxation occurs through 5-HT 4 activation in bovine peripheral vasculature.
(© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)
Databáze: MEDLINE
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