A Case of Rapid Successfully Treated Hypertension with Chotosan under the Treatment of Tinnitus / 日本東洋医学雑誌

The case was a 70-years-old man whose chief complaint was tinnitus. After the administration of chotosan, his tinnitus was improved in 10 months. In addition, his headache, which had not been his main complaint, also disappeared. However, hypertension, which had not been reported in his history, was newly observed, when his chotosan dosage was reduced. After the usual dosage of chotosan was prescribed again, his blood pressure promptly decreased from the day that the administration started. Chotosan can improve tinnitus, especially in elderly people. Furthermore, this case suggested that chotosan is potentially useful as a primary medication in mild hypertension, when there are no severe coexisting illnesses. And, it may exhibit its anti-hypertensive effects quite rapidly.

Possible Involvement of Ca2+ Activated K+ Channels, SK Channel, in the Quercetin-Induced Vasodilatation

Effects of quercetin, a kind of flavonoids, on the vasodilating actions were investigated. Among the mechanisms for quercetin-induced vasodilatation in rat aorta, the involvement with the Ca2+ activated K+ (KCa) channel was examined. Pretreatment with NE (5 micrometer) or KCl (60 mM) was carried out and then, the modulation by quercetin of the constriction was examined using rat aorta ring strips (3 mm) at 36.5degrees C. Quercetin (0.1 to 100 micrometer) relaxed the NE-induced vasoconstrictions in a concentration-dependent manner. NO synthesis (NOS) inhibitor, NG-monomethyl-L-arginine acetate (L-NMMA), at 100 micrometer reduced the quercetin (100 micrometer)-induced vasodilatation from 97.8+/-3.7% (n=10) to 78.0+/-11.6% (n=5, p<0.05). Another NOS inhibitor, L-NG-nitro arginine methyl ester (L-NAME), at 100 micrometer also had the similar effect. In the presence of both 100 micrometer L-NMMA and 10 micrometer indomethacin, the quercetin-induced vasodilatation was further attenuated by 100 micrometer tetraethylammonium (TEA, a KCa channel inhibitor). Also TEA decreased the quercetin-induced vasodilatation in endothelium-denuded rat aorta. Used other KCa channel inhibitors, the quercetin-induced vasodilatation was attenuated by 0.3 micrometer apamin (a SK channel inhibitor), but not by 30 nM charybdotoxin (a BK and IK channel inhibitor). Quercetin caused a concentration-dependent vasodilatation, due to the endothelium-dependent and -independent actions. Also quercetin contributes to the vasodilatation selectively with SK channel on smooth muscle.