• The Journal of Korean Medicine
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• v.25 no.4
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• pp.1-7
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• 2004

Objective : This study was designed to examine the effects of orally administered Prunus persica water extract (PPE), which is used as herbal medicine, for treatment of Yu Xue (stasis of blood) and tacrine on the basal concentration of extracellular acetylcholine in the hippocampus of rats. Methods: To investigate the effects of PPE and tacrine on concentration of extracellular acetylcholine in the hippocampus of rats, the microdialysis technique, under the same experimental conditions, was used. And we used male Wistar rats which were 7 weeks of age and 210-290 g. PPE was extracted with boiling water, and the rats were anesthetized with pentobarbital Na. Their skulls were exposed and a hole was drilled for implantation of a microdialysis probe. In order to increase the recovery of acetylcholine, a probe with a long membrane was used. One day after surgery, the microdialysis probe was perfused with Ringer's solution at a flow rate of 1.5 l/min. The acetylcholine concentration in dialysis samples was measured by high-performance liquid chromatography (HPLC) with electrochemical detection. AChE activity was measured using the radiometric method, as described by Sherman. Results : The comparative effects of PPE and tacrine on hippocampal extracellular acetylcholine concentration was that these cholinesterase inhibitors produced dose-dependent increases in the extracellular acetylcholine concentration. And the effect of PPE and tacrine on rat brain AChE activity was that PPE produced maximal inhibition at 1 h after administration, when AChE activity was 44% of the intact level. AChE activity gradually recovered thereafter, and reached 78% of the intact level at 12 h after administration. Conclusion : In this study, PPE has a potent activity and a long-lasting effect on the central cholinergic system, in terms of the basal concentration of extracellular acetylcholine in the hippocampus and the AChE activity in the brain of rats. And oral administration of PPE increased dose-dependently the basal concentration of extracellular acetylcholine in the hippocampus of rats. PPE may be one of the more useful cholinesterase inhibitors for the treatment of Alzheimer's disease.

• Journal of fish pathology
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• v.9 no.1
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• pp.53-63
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• 1996

The present study was undertaken to investigate the physiological characteristics of the cholinergic responses in the tilapia dorsal aorta. In vessels under resting tension or precontracted with norepinephrine, acetylcholine caused only concentration-dependent vasoconstrictions. Contractile response to acetylcholine was not affected by the removal of endothelium or the application of methylene blue. Atropine, gallamine or pirenzepine shifted concentration-response curve to the right. However pirenzepine showed a similar effect on the curve only at high concentration ($1{\times}10^{-5}$M). Acetylcholine-induced vasoconstriction was not markedly influenced by indomethacin, or verapamil, but was almost abolished in the calcium-free physiological buffer solution. These results suggest that acetylcholine produces only an endothelium-independent vasoconstriction in tilapia dorsal aorta and that the contractile effect of acetylcholine is mainly mediated by the activation of $M_2$ subtype receptor, which might be associated with the extracellular calcium influx through receptor-linked calcium channel.

• Journal of Plant Biology
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• v.19 no.1
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• pp.14-18
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• 1976

Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

• The Journal of Internal Korean Medicine
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• v.17 no.1
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• pp.193-203
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• 1996

These studies were carried out to investigate the effect of Insameumja water extract on the inhibitory contractile action of acetylcholine in guinea pig. The results of these studies were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in guinea pig was significantly inhibited by Insameumja. 2. Dose-response of acetylcholine pretreated Insameumja in guinea pig was not significantly changed. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in guinea pig was decreased. 4. Inhibitory contractile action of acetylcholine pretreated indomethacin was significantly changed by Insameumja. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue was not significantly changed by Insameumja.

• The Journal of Internal Korean Medicine
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• v.16 no.2
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• pp.92-100
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• 1995

These studies were carried out to investigate the effect of Mahwangchangchultang water extract on the inhibitory contractile action of acetylcholine in guinea pig. The results of these studies were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in guinea pig was significantly inhibited by Mahwangchangchultang 2. Dose-response of acetylcholine pretreated Mahwangchangchultang in guinea pig was not significantly changed. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in guinea pig was decreased. 4. Inhibitory contractile action of acetylcholine pretreated indomethacin was not significantly changed by Mahwangchangchultang. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue was not significantly changed by Mahwangchangchultang.

• The Journal of Internal Korean Medicine
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• v.16 no.1
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• pp.146-159
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• 1995

These studies were carried out to investigate the effect of Chunggeumeum water extract on the inhibitory contractile action of acetylcholine in guinea pig. The results of these studies were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in guinea pig was significantly inhibited by Chunggeumeum. 2. Dose-response of acetylcholine pretreated Chunggeumeum in guina pig was not significantly changed. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in guinea pig was decreased. 4. Inhibitory contractile action of acetylcholine pretreated indomethacin was not significantly changed by Chunggeumeum. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue was not significantly changed by Chunggeumeum.

• The Journal of Dong Guk Oriental Medicine
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• v.4
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• pp.267-311
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• 1995

This study was performed to analyze the effects of WhoaDam-JiHae PyeongChunYak on contracted tracheal smooth muscle in rat. Transverse strips were used for the experiment using organ bath. The test strip was perfused with modified Krebs-Ringer Bicarbonate solution which was aerated with 95% $O_2$-5% $CO_2$ mixed gas and kept at $37^{\circ}C$. WhoaDam-JiHae PyeongChunYak extract and acetylcholine infused tracheal strip that was contracted with acetylcholine. The results were as follows : 1. The contractile force of tracheal strip by acetylcholine was significantly increased by Pinelliae Rhizoma, Arisaematis Rhizoma, Sinapis Semen. Typhonii Rhizoma, Peucedani Radix, Eriobotryae Folium, Platycodi Radix, Bambusae Caulis Taeniam, Benincasae Semen, Armeniacae Amarum Semen, Asteris Radix, Periliae Fructus, Mori cortex and Lepidii Semen. 2. Arisaematis Rhizoma($1{\mu}{\ell}/m{\ell}$, $3{\mu}{\ell}/m{\ell}$, $10{\mu}{\ell}/m{\ell}$) and Asteris Radix($1{\mu}{\ell}/m{\ell}$, $3{\mu}{\ell}/m{\ell}$) slightly relaxed the contracted tracheal strip by acetylcholine. 3. Farfarae Flos significantly relaxed the contracted tracheal strip by acetylcholine. 4. The contractile force of tracheal strip by acetylcholine was significantly increased by Stemonae Radix at $30{\mu}{\ell}/m{\ell}$, on the other hand Stemonae Radix at $100{\mu}{\ell}/m{\ell}$ significantly relaxed the contracted tracheal strip by acetylcholine.

• YAKHAK HOEJI
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• v.56 no.4
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• pp.222-229
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• 2012

In order to determine acetylcholine and choline in the biological samples, the specific enzymes of acetylcholinesterase (AChE) and choline oxidase (ChO), which utilize acetylcholine and choline as substrates, were employed to convert substrates to $H_2O_2$. The produced $H_2O_2$ was coupled to 4-aminoantipyrine/phenol with peroxidase (PO) yielding quinoneimine dye which was measured at 508 nm. In the present enzymatic spectrophotometric analysis the product at the equilibrium state was measured considering accuracy, precision, time and cost of the analysis. The developed analytical method yielded good linearity (calibration curve; $A_{508}$=9534[acetylcholine]+0.009, correlation coefficient ($R^2$); 0.999) with detection limit of $1.11{\times}10^{-7}M$, reasonable precision (relative standard deviation; 0.10~1.62% at $2.5{\times}10^{-6}M{\sim}1.25{\times}10^{-4}M$) and accuracy (relative error; -0.24~0.97% at $4.13{\times}10^{-6}M{\sim}1.01{\times}10^{-4}M$) for acetylcholine chloride standard solution. The concentrations of acetylcholine and choline in human serum were found as $3.20{\times}10^{-5}M$ and $1.14{\times}10^{-4}M$, respectively. The brain tissues of Sprague-Dawley strain rat contained 9.82${\mu}g/g$ of acetylcholine and 6.53 ${\mu}g/g$ of choline in the cerebrum, while 7.37 ${\mu}g/g$ of acetylcholine and 5.34 ${\mu}g/g$ of choline in the cerebellum.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.179-179
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• 1996

The involvement of the cyclic AMP (cAMP) effector system in the release of endogenous dopamine and acetylcholine from the rat neostriatum was assessed. Forskolin, an activator of adenylate cyclase, was used to enhance CAMP production, and the consequence of this enhancement on the spontaneous and potassium stimulated release of dopamine and acetylcholine was evaluated. Neostriatal slices were prepared from Fischer 344 rats and after a preincubation period the release of each endogenous neurotransmitter was measured from the same slice preparation. To measure acetylcholine release the slice acetylcholinesterase (AChE) activity was inhibited with physostigmine, but the release from slices with intact AChE activity was also determined (choline, instead of acetylcholine was detected in the medium). Under both conditions forskolin induced a significant dose-dependent increase in the potassium-evoked release of dopamine. In the same tissue preparations the release of neither acetylcholine (AChE inhibited) nor choline (AChE intact) was affected by forskolin. The results indicate that the cAMP second messenger system is involved ill neuronal mechanisms that enhance neuronal dopamine release, but stimulation of this second messenger by forskolin does not further enhance neostriatal acetylcholine release.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.4
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• pp.195-201
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• 2011

The flavonoid quercetin is a low molecular weight compound generally found in apple, gingko, tomato, onion and other red-colored fruits and vegetables. Like other flavonoids, quercetin has diverse pharmacological actions. However, relatively little is known about the influence of quercetin effects in the regulation of ligand-gated ion channels. Previously, we reported that quercetin regulates subsets of nicotinic acetylcholine receptors such as ${\alpha}3{\beta}4$, ${\alpha}7$ and ${\alpha}9{\alpha}10$. Presently, we investigated the effects of quercetin on muscle-type of nicotinic acetylcholine receptor channel activity expressed in Xenopus oocytes after injection of cRNA encoding human fetal or adult muscle-type of nicotinic acetylcholine receptor subunits. Acetylcholine treatment elicited an inward peak current ($I_{ACh}$) in oocytes expressing both muscle-type of nicotinic acetylcholine receptors and co-treatment of quercetin with acetylcholine inhibited $I_{ACh}$. Pre-treatment of quercetin further inhibited $I_{ACh}$ in oocytes expressing adult and fetal muscle-type nicotinic acetylcholine receptors. The inhibition of $I_{ACh}$ by quercetin was reversible and concentration-dependent. The $IC_{50}$ of quercetin was $18.9{\pm}1.2{\mu}M$ in oocytes expressing adult muscle-type nicotinic acetylcholine receptor. The inhibition of $I_{ACh}$ by quercetin was voltage-independent and non-competitive. These results indicate that quercetin might regulate human muscle-type nicotinic acetylcholine receptor channel activity and that quercetin-mediated regulation of muscle-type nicotinic acetylcholine receptor might be coupled to regulation of neuromuscular junction activity.