著者

Tomio Okamura Masashi Tawa Ayman Geddawy Takashi Shimosato Hirotaka Iwasaki Haruo Shintaku Yuichi Yoshida Masahiro Masada Kazuya Shinozaki Takeshi Imamura

出版者

The Japanese Pharmacological Society

雑誌

Journal of Pharmacological Sciences (ISSN:13478613)

巻号頁・発行日

vol.124, no.1, pp.76-85, 2014-01-20 (Released:2014-01-18)

参考文献数

41

被引用文献数

10 21

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Deficiency of tetrahydrobiopterin (BH4) in the vascular tissue contributes to endothelial dysfunction through reduced eNOS activity and increased superoxide anion (O2−) generation in the insulin-resistant state. We investigated the effects of atorvastatin, a 3-hydroxyl-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor; amlodipine, a calcium antagonist; and their combination on blood pressure, arterial relaxation and contraction, and vascular oxidative stress in aortas of high fructose–fed rats. Oral administration of atorvastatin for 8 weeks did not significantly lower blood pressure, but normalized angiotensin II–induced vasoconstriction and endothelial function in the fructose-fed rats. Atorvastatin treatment of fructose-fed rats increased vascular BH4 content, which was associated with an increase in endothelial NO synthase activity as well as a reduction in endothelial O2− production. On the other hand, administration of amlodipine did not affect the angiotensin II–induced vasoconstriction and endothelial function, but normalized the elevated blood pressure in the fructose-fed rats. The combined treatment did not show synergistic but additive beneficial effects. The present study suggests that combined therapy of HMG-CoA reductase inhibitors and calcium antagonists prevents functional vascular disorders in the insulin-resistant state, possibly resulting in the protection against or delay of development of hypertension, vascular dysfunction in diabetes, and thereafter atherosclerosis.

著者

Seiji INOUE Ka BIAN Tomio OKAMURA Hideki OKUNISHI Noboru TODA

出版者

(社)日本薬理学会

雑誌

The Japanese Journal of Pharmacology (ISSN:00215198)

巻号頁・発行日

vol.50, no.3, pp.271-282, 1989 (Released:2006-08-25)

参考文献数

24

被引用文献数

7 9

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Effects of eperisone, an antispasmodic in skeletal muscle, were investigated in helical strips of dog saphenous artery and vein. Eperisone relaxed saphenous arteries and veins previously contracted with norepinephrine, serotonin, acetylcholine, K+, or Ba2+; but in contrast, it produced contractions in the blood vessels contracted with prostaglandin (PG) F2α. Treatment with eperisone attenuated the contractions induced by norepinephrine and serotonin in the arteries and those by clonidine and phenylephrine in the veins. Eperisone inhibited angiotensin II-induced relaxations, mediated possibly by endogenous PGI2, but did not alter relaxations caused by exogenous PGI2. Treatment with eperisone (10-5 M) potentiated the contractile response to electrical stimulation of adrenergic nerves; the potentiating effect was suppressed by yohimbine. The eperisone-induced contraction in PGF2α-contracted arteries was inhibited by treatment with indomethacin or aspirin, although cyclooxygenase activity was not inhibited by eperisone. These results may indicate that eperisone blocks postjunctional α1- and α2-adrenergic, muscarinic, serotonergic receptors and prejunctional α2 adrenoceptors and reduces PGI2 synthesis via a mechanism other than cyclooxygenase inhibition.