Blood-Pressure Lowering,Positive Chronotropy and Inotropy by the Veratrum Alkaloids Germidine and Germerine but Negative Chronotropy by Veratridine in Mice |
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| Authors: | Md Amirul Islam Ritsu Honda Hiroshi Nojima Yasuhiro Tezuka Weijie Zhao |
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| Institution: | 1. Department of Chemical Pharmacology , Institute of Natural Medicine, Toyama Medical and Pharmaceutical University , 2630, Sugitani, Toyama, 930-0194, Japan;2. Department of Natural Products Chemistry , Institute of Natural Medicine, Toyama Medical and Pharmaceutical University , 2630, Sugitani, Toyama, 930-0194, Japan;3. Research Institute for Medical and Pharmaceutical Sciences , Dalian, Chunyangjie, 21, China |
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| Abstract: | Abstract Germidine and germerine, the Veratrum alkaloids lowered blood pressure accompanied with positive chronotropy and inotropy in mice. Germerine was more potent than germidine in both blood-pressure lowering and positive inotropy, whereas veratridine produced negative chronotropy and positive inotropy. An acyl group (an acetyl or a 2-methylbutyroyl group) at 3-O-R1 position and a 2-methylbutyroyl group at 15-O-R2 position in germine were important to produce the positive inotropy and chronotropy. The presence of a veratroyl group at 3-O-R1 position and a free hydroxyl group at 15-O-R2 position may be essential to produce the negative chronotropy by veratridine. The positive inotropy by germidine and veratridine may be due to TTX-resistant Na+ channel activation. |
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| Keywords: | Germidine Germerine Blood-pressure lowering Positive inotropy Positive chronotropy |
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