| English |
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| Title | Effect of Acidosis on Vasoconstrictors and Vasodilators in Rat Aortic Rings |
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| Subtitle | |
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| Authors | Shinichi Dozaki, Yoshihiro Ohta, Osamu Kemmotsu |
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| Authors(kana) | |
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| Organization | Department of Anesthesiology and Intensive Care, Hokkaido University School of Medicine |
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| Journal | Circulation Control |
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| Volume | 18 |
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| Number | 4 |
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| Page | 561-566 |
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| Year/Month | 1997/ |
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| Article | Original article |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | [Abstract] Although acidosis induces vasodilation and attenuation of the effects of several cardiovascular drugs, a quantitative analysis of the effect of acidosis on vasoconstrictors and / or vasodilators has not been conducted. In this study we used rat aortic rings to evaluate the effect of pH on vascular contraction following administration of phenylephrine, dopamine and potassium chloride (KCl) and also on the vasodilating action of prostaglandin E1 (PGE1) and nicardipine. Thoracic aortic rings obtained from male Sprague-Dawley rats (N=20) were suspended in an organ bath containing HEPES solution (37℃) aerated with 100% O2. Contractile responses to phenylephrine 3×10-7M, dopamine 3×10-5M and KCl 40mM were obtained in each pH solution (7.4, 7.0, 6.6 and 6.2). Relaxation responses with increasing doses of PGE1 and nicardipine concentrations were also obtained. The contractive response in pH6.2 solutions was 17±4.5%, 37±6.3% and 71±4.9% of control which the tension obtained at pH7.4 was regarded as 100% in the phenylephrine, dopamine and KCl groups, respectively. PGE1 produced dose dependent vasodilation in pH6.2 solution only, which suggested that acidosis could not attenuate the vasodilating action of PGE1. Nicardipine exhibited a vasodilatory effect in each pH solution. The results demonstrated that acidosis itself attenuated the vasoconstrictive effects of phenylephrine and dopamine, and that KCl and nicardipine could maintain their pharmacological actions but PGE1 showed a complicated action in acidosis. |
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| Practice | Basic medicine |
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| Keywords | Acidosis, Aortic ring, Rat, Vasoconstrictors (phenylephrine, dopamine, KCl), Vasodilators (prostaglandin E1, nicardipine) |
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