碩士 / 國立陽明大學 / 藥理學研究所 / 87 / Abstract
Acori Graminei Rhizoma (AGR) has been used traditionally in the treatment of amnesia in China for more than thousand years. Previous study has demonstrated that the water extract of AGR significantly promots memory performance and attenuats scopolamine-induced amnesia on step-through passive avoidance tasks in mice. As some anti-amnestic drugs have been shown to enhance the cholinergic transmission in the hippocampus, an isolated hippocampal slices experimental model was established to evaluate the effect of AGR water extract on hippocampal acetylcholine (ACh) release. In addition, previous study has indicated that AGR contains the principles acting on the 5-HT (5-HT1A, 5-HT2), dopamine (D1, D2), and nicotinic receptors, the effects of these receptor agonists were also evaluated. [3H]Choline labeled hippocampal slices (500 mm) were stimulated with 40 mM K+ to evaluate the effects of above-mentioned drugs on [3H]ACh release. The results indicated that 5-HT (0.2~20 mM) , 5-HT1A receptor agonist 8-OH-DPAT (0.2~20 mM) and 5-HT2 receptor agonist 5-methyl-5-HT (1~10 mM) had no significant effects on both basal and high potassium-evoked [3H]ACh releases. D1 receptor agonist SKF 38393 (0.1~10 mM) had no significant effects on both basal and high potassium-evoked [3H]ACh releases. However, although D2 receptor agonist quinpirole (0.1~1 mM) had no effect on basal release, it concentration-dependently inhibited high potassium-evoked [3H]ACh release with a maximal inhibitory effect of 30 %. Nicotinic receptor agonist nicotine (1~100 mM) had no effects on both basal and high potassium-evoked [3H]ACh releases. However, although muscarinic receptor agonist carbachol (1~100 mM) had no effect on basal release, it concentration-dependently inhibited high potassium-evoked [3H]ACh release (27.2±3.6 %~67.3±4.7 % inhibition), which was completely abolished by the antagonist atropine. On the other hand, atropine (100 mM) and another antagonist scopolamine (100 mM) inhibited high potassium-evoked [3H]ACh release by 41.0±6.2 % and 17.0±1.6 %, respectively. The AGR water extract concentration-dependently increased the basal release, but had no enhancing effect on high potassium-evoked [3H]ACh release. It even inhibited high potassium-evoked [3H]ACh release at higher concentration (150 mg/ml). Therefore, the present results indicated that AGR increases basal release of [3H]ACh in hippocampal slices may not be via the activation of above-mentioned receptors.
| Identifer | oai:union.ndltd.org:TW/087YM000550017 |
| Date | January 1999 |
| Creators | Yiu-Ching Chung, 鍾耀清 |
| Contributors | Jyh-Fei Liao, 廖志飛 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 58 |
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