Park KE, Sohn JT, Jeong YS, Sung HJ, Shin IW, Lee HK, Chung YK. Inhibitory effect of fentanyl on phenylephrine-induced contraction of the rat aorta.
Yonsei Med J 2009;
50:414-21. [PMID:
19568605 PMCID:
PMC2703766 DOI:
10.3349/ymj.2009.50.3.414]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 10/03/2008] [Accepted: 10/03/2008] [Indexed: 11/27/2022] Open
Abstract
PURPOSE
Fentanyl was reported to inhibit the alpha(1)-adrenoceptor agonist-induced contraction. The goal of this in vitro study was to identify the alpha(1)-adrenoceptor subtype primarily involved in the fentanyl-induced attenuation of phenylephrine-induced contraction in isolated endothelium-denuded rat aorta.
MATERIALS AND METHODS
Aortic rings were suspended in order to record isometric tension. Concentration-response curves for phenylephrine (10(-9) to 10(-5) M) were generated in the presence or absence of one of the following drugs: fentanyl (3 x 10(-7), 10(-6), 3 x10(-6) M), 5-methylurapidil (3 x10(-8), 10(-7), 3 x 10(-7) M), chloroethylclonidine (10(-5) M) and BMY 7378 (3 x 10(-9), 10(-8), 3 x 10(-8) M). Phenylephrine concentration-response curves were generated in the presence or absence of fentanyl in rings pretreated with either 3 x10(-9) M prazosin, 10(-9) M 5-methylurapidil or 3 x 10(-9) M BMY 7378.
RESULTS
Fentanyl (10(-6), 3 x 10(-6) M) attenuated phenylephrine-induced contraction in the rat aorta. 5-Methylurapidil and BMY 7378 produced a parallel rightward shift in the phenylephrine concentration-response curve. The pA(2) values for 5-methylurapidil and BMY 7378 were estimated to be 7.71 +/- 0.15 and 8.99 +/- 0.24, respectively. Fentanyl (10(-6) M) attenuated phenylephrine-induced contraction in rings pretreated with 10(-9) M 5-methylurapidil, but did not alter the rings when pretreated with 3 x 10(-9) M BMY 7378. Pretreatment of the rings with chloroethylclonidine showed a 72.9 +/- 2.3% reduction in phenylephrine-induced maximal contraction.
CONCLUSION
The results suggest that fentanyl attenuates phenylephrine-induced contraction by inhibiting the pathway involved in the alpha(1D)-adrenoceptor-mediated contraction of the rat aorta.
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