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Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro

BACKGROUND: Studies in vivo have shown that dexmedetomidine (DEX) could protect the myocardium and modulate the coronary blood flow. This study aimed to investigate the direct and concentration-dependent effects of DEX on the tone of porcine coronary artery in vitro and the underlying mechanisms. MA...

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Autores principales: Zhou, Shu-Zhi, Li, Zhi-Ming, Liu, Xue-Ru, Zhou, Jun, Tan, Xiao-Qiu, Yang, Yan, Wei, Ji-Cheng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: International Scientific Literature, Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5388309/
https://www.ncbi.nlm.nih.gov/pubmed/28369032
http://dx.doi.org/10.12659/MSM.903501
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author Zhou, Shu-Zhi
Li, Zhi-Ming
Liu, Xue-Ru
Zhou, Jun
Tan, Xiao-Qiu
Yang, Yan
Wei, Ji-Cheng
author_facet Zhou, Shu-Zhi
Li, Zhi-Ming
Liu, Xue-Ru
Zhou, Jun
Tan, Xiao-Qiu
Yang, Yan
Wei, Ji-Cheng
author_sort Zhou, Shu-Zhi
collection PubMed
description BACKGROUND: Studies in vivo have shown that dexmedetomidine (DEX) could protect the myocardium and modulate the coronary blood flow. This study aimed to investigate the direct and concentration-dependent effects of DEX on the tone of porcine coronary artery in vitro and the underlying mechanisms. MATERIAL/METHODS: Distal branches of the porcine anterior descending coronary arteries were dissected and cut into 3–5 mm rings. The tones of coronary rings in response to cumulative DEX were measured using the PowerLab system. Coronary rings were divided into three groups: 1) endothelium-intact coronary rings without drug pretreatment (control); 2) endothelium-intact coronary rings pretreated with either yohimbine, tetraethylamine (TEA) or NG-nitro-L-arginine methyl ester (L-NAME); and 3) endothelium-denuded coronary rings pretreated with either yohimbine or TEA. RESULTS: DEX induced coronary ring relaxation at lower concentrations (10(−9) to 10(−7) M) followed by constriction at higher concentrations (10(−6) to 10(−5) M). The coronary constrictive effect of higher DEX (10(−5) M) was greater in the endothelium-denuded rings than in the endothelium-intact rings. Yohimbine reduced the coronary constrictive effect of DEX at higher concentrations (10(−6) to 10(−5) M). TEA and L-NAME significantly reduced the coronary relaxing effect of DEX at lower concentrations (10(−9) to 10(−7) M) in endothelium-intact rings. TEA attenuated the coronary relaxation induced by DEX in endothelium-denuded rings. CONCLUSIONS: DEX exerts bidirectional effects on porcine coronary tone. The coronary relaxing effect of DEX at lower concentrations is likely associated with endothelium integrity, NO synthesis and BKCa channel activation, while the coronary constrictive effect of DEX at higher concentrations is mediated by α2 adrenoceptors in the coronary smooth muscle cells.
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spelling pubmed-53883092017-04-13 Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro Zhou, Shu-Zhi Li, Zhi-Ming Liu, Xue-Ru Zhou, Jun Tan, Xiao-Qiu Yang, Yan Wei, Ji-Cheng Med Sci Monit Lab/In Vitro Research BACKGROUND: Studies in vivo have shown that dexmedetomidine (DEX) could protect the myocardium and modulate the coronary blood flow. This study aimed to investigate the direct and concentration-dependent effects of DEX on the tone of porcine coronary artery in vitro and the underlying mechanisms. MATERIAL/METHODS: Distal branches of the porcine anterior descending coronary arteries were dissected and cut into 3–5 mm rings. The tones of coronary rings in response to cumulative DEX were measured using the PowerLab system. Coronary rings were divided into three groups: 1) endothelium-intact coronary rings without drug pretreatment (control); 2) endothelium-intact coronary rings pretreated with either yohimbine, tetraethylamine (TEA) or NG-nitro-L-arginine methyl ester (L-NAME); and 3) endothelium-denuded coronary rings pretreated with either yohimbine or TEA. RESULTS: DEX induced coronary ring relaxation at lower concentrations (10(−9) to 10(−7) M) followed by constriction at higher concentrations (10(−6) to 10(−5) M). The coronary constrictive effect of higher DEX (10(−5) M) was greater in the endothelium-denuded rings than in the endothelium-intact rings. Yohimbine reduced the coronary constrictive effect of DEX at higher concentrations (10(−6) to 10(−5) M). TEA and L-NAME significantly reduced the coronary relaxing effect of DEX at lower concentrations (10(−9) to 10(−7) M) in endothelium-intact rings. TEA attenuated the coronary relaxation induced by DEX in endothelium-denuded rings. CONCLUSIONS: DEX exerts bidirectional effects on porcine coronary tone. The coronary relaxing effect of DEX at lower concentrations is likely associated with endothelium integrity, NO synthesis and BKCa channel activation, while the coronary constrictive effect of DEX at higher concentrations is mediated by α2 adrenoceptors in the coronary smooth muscle cells. International Scientific Literature, Inc. 2017-04-03 /pmc/articles/PMC5388309/ /pubmed/28369032 http://dx.doi.org/10.12659/MSM.903501 Text en © Med Sci Monit, 2017 This work is licensed under Creative Common Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
spellingShingle Lab/In Vitro Research
Zhou, Shu-Zhi
Li, Zhi-Ming
Liu, Xue-Ru
Zhou, Jun
Tan, Xiao-Qiu
Yang, Yan
Wei, Ji-Cheng
Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title_full Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title_fullStr Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title_full_unstemmed Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title_short Bidirectional Regulatory Effects of Dexmedetomidine on Porcine Coronary Tone In Vitro
title_sort bidirectional regulatory effects of dexmedetomidine on porcine coronary tone in vitro
topic Lab/In Vitro Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5388309/
https://www.ncbi.nlm.nih.gov/pubmed/28369032
http://dx.doi.org/10.12659/MSM.903501
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