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In vitro vasoactive effects of dexmedetomidine on isolated human umbilical arteries

2019; AEPress; Volume: 120; Issue: 01 Linguagem: Inglês

10.4149/bll_2019_006

1336-0345

Oğuzhan Arun, S. B. Taylan, İpek Duman, Bahar Öç, Setenay Arzu Yılmaz, Ahmet Tekin, Çiğdem Çelik, Hülagu Barışkaner, Jale Bengi Çelik,

Analytical Chemistry and Sensors

OBJECTIVE: We aimed to investigate the vasoactive effects of dexmedetomidine on isolated human umbilical arteries and possible mechanisms involved.METHODS: Human umbilical artery strips were suspended in Krebs-Henseleit solution and dose-response curves were obtained for cumulative dexmedetomidine before and after incubation with different agents; propranolol, atropine, yohimbine, prazosin, indomethacin, verapamil.Effects of calcium on cumulative dexmedetomidineinduced contractions were also studied.RESULTS: Cumulative dexmedetomidine resulted in dose dependent contraction responses.Incubation with propranolol (Emax: 93.3 ± 3.26 %), atropine (Emax: 92.0 ± 6.54 %), or indomethacin (Emax: 94.25 ± 2.62 %), did not attenuate dexmedetomidine-elicited contractions (p > 0.05).There were signifi cant decreases in the contraction responses of cumulative dexmedetomidine with yohimbine (Emax: 12.1 ± 11.9 %), prazosin (Emax: 28.8 ± 4.6 %) and verapamil (Emax: 11.2 ± 13.6 %) (p < 0.05).In Ca +2 free medium contraction responses to cumulative dexmedetomidine was insignifi cant (Emax: 5.20 ± 3.42 %).Addition of cumulative calcium to the Ca +2 free medium resulted in concentration dependent increase in contractions (Emax: 64.83 ± 37.7 %) (p < 0.05).CONCLUSION: Dexmedetomidine induces vasoconstriction in endothelial-free umbilical arteries via both, α 1and α 2 -adrenergic receptors and also extracellular Ca +2 concentrations play a major role.β-adrenergic receptors, muscarinic cholinergic receptors, and inhibition of cyclooxygenase enzyme are not involved in this vasoconstriction (Fig. 3, Ref. 36).