• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.137-137
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• 2002

Several epidemiologidal studies suggested that arsenic exposure was strongly correlated with the development of cardiovascular disease such as hypertension. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation using the isolated rat aortic ring in in vitro organ bath system. Treatment with arsenite inhibited acetylcholine-induced relaxation of aortic rings in a concentration- dependent manner. The inhibitory effects by arsenic were also observed in the relaxation induced by sodium nitroprusside, a NO-donor. Consistent with these findings, the cGMP levels stimulated by acetylcholine in blood vessels were reduced significantly by arsenite treatment. In addition, higher concentration of arsenite decreased the relaxation by 8-Br-cGMP, a cGMP analog, in aortic rings without endothelium. These in vitro results indicated that arsenite that arsenite was capable of suppressing acetylcholine-induced relaxation in blood vessels by inhibiting production of nitric oxide in endothelial cells and by impairing the relaxation machinary in smooth muscle cells. In vivo studies revealed that the reduction of blood pressure by acetylcholine infusion was signigicantly suppressed after arsenite was administered intravenously to rate. These data suggest that vasomotor tone impaired by arsenite exposure may be one of the contrbuting factors in development of cardiovascular disease.

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.81-85
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• 1999

Diazinon, an organophosphate pesticide, is relatively highly toxic to fish and causes vertebral malformation and behavioral change of fish at relatively low concentrations. To elucidate biochemical mechanism of the behavioral change of Oryzias latipes (killifish) caused by diazinon, the effect of the insecticide on acetylcholine esterase activities and the levels of some neurotransmitters were evaluated. Acetylcholine esterase activities in both head and body were significantly lowered at the concentration of 10 ppb of diazinon and acetylcholine contents in head tended to be upregulated with increasing concentration of diazinon. Exposure of killifish to 5000 ppb diazinon resulted in gradual decrease in acetylcholine content in body part with exposure time. Norepinephrine and serotonin concentrations in killifish head and body were highest at 1000 ppb of diazinon while neurotransmitter were relatively low in fish unexposed or exposed to lower dose of the pesticide, suggesting that increased norepinephrine and serotonin can partially account for diazinon-induced behavioral abnormality.

• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.71-76
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• 1983

Aminoglycoside antibiotics are reported to enhance the amylase release from isolated slices of pancreas in vitro and the mode of action of aminoglycosides on amylase release is considered different from those of acetylcholine or cholecystokinin(CCK), i.e., electronmicroscopically intact zymogen granules are appeared in the lumen of pancreatic acini by treatment of aminoglycosides. It is known that atropine blocks the secretagogue effect of acetylcholine, and phenoxybenzamine is reported to block the effects of CCK or its analogue caerulein. Present study was undertaken to investigate the mode of action of aminoglycosides on the amylase release using atropine, phenoxybenzamine and propranolol as a membrane stabilizing agent in slices of chicken pancreas. The results are summarized as follows : 1) Streptomycin and kanamycin increased the amylase release significantly from slices of chicken pancreas. 2) The effect of streptomycin was inhibited by atropine but not by phenoxybenzamine or propranolol. 3) The amylase release by acetylcholine was blocked by atropine tut the effect of cholecystokinin octapeptide(CCK-8) was not influenced by atropine, phenoxybenzamine or propranolol. 4) Pretreatment of streptomycin enhanced the secretagogue effect of acetylcholine or CCK-8. From these results it is suggested that amylase releasing effects of aminoglycosides are mediated in part by cholinergic stimulation and in part by membrane alteration and these effects are enhanced by acetylcholine or cholecystokinin.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1236-1242
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• 2002

In order to make an efficient prescription and cope with dementia, learning and memory functions of Sprague-Dawley model rats were tested with Morris water maze. And to evaluate the effect of the sample drug(CHM) on choline acetyltranferase and acetylcholine esterase, immunoreactive measurement and enzymatic activity measuring were carried out. Rats were injected with ibotenic acid through hippocampus CA1 and CA3 area. The results are as following. CHM improves the learning ability in the acquisition test and memory function in the retention test significantly. And CHM increases the level of AChE which is resolving acetylcholine. Though it doesn't increase the level of ChAT significantly which is synthesizing acetylcholine, but it shows the tendency of increase. So these results show that CHM improve the cholinergic catabolism and anabolism, and the increment of metabolic activity of cholinergic system. Thus it can be concluded that CHM will be helpful to cholinergic brain disease induced by primary or senile reduction of acetylcholine secretive activity.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.113-118
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• 2000

TEA, glibenclamide, L-NAME and SKF 525A-induced reversible contraction were investigated using acetylcholine, sodium nitroprusside (SNP) and pinacidil in rat abdominal and thoracic aorta. Acetylcho-line, SNP or pinacidil produced in a dose dependent manner relaxation on phenylephrine-induced contraction In rat aorta. TEA, SKF 525A, and L-NAME produced reversible contractions on acetylcholine-induced relaxation, but not on SNP- or pinacidil-induced relaxation. Glibenclamide significantly produced reversible con- traction on pinacidll-induced relaxation. The reversible effect of TEA on the acetylcholine-induced relaxation was reduced by SKF 525A. These results indicate that the acetylcholine-induced relaxation may be mediated by NO, cytochrome P$_{450}$-dependent epoxygenase pathway, or $Ca^{2+}$ activated $K^{+}$ channel, and the pinacidil-induced relaxation may be mediated by ATP-sensitive $K^{+}$ channel.annel.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.111-111
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• 1995

1. 혈압 및 맥박 실험 Acetylcholine과 상엽 수층분획을 단독으로 정맥에 투여한 경우 각각에서 농도 의존적으로 일시적인 혈압 강하 효과가 나타났고 빈맥 현상이 관찰되었다. Nitric Oxide 합성효소 억제제인 N$^{G}$ -Nitro-L-Arginine Methyl Ester(10 mg/kg I. v)를 전처리한 경우 위 두 약물에 의한 혈압강하효과는 공히 증가되어졌다. 또한 두 약물에 의한 혈압강하 효과는 Atropine Sulfate(1 mg/kg i.v) 전처리로 완전히 차단되었다. Cholinesterase 억제제인 Physostigmine (0.05 mg/kg i.v) 전처리는 상엽의 혈압강하 효과에 아무런 영향을 나타내지 못하였다. 2. 장관 실험 Acetylcholine과 상엽 수층분획을 organ bath에 첨가한 경우 각각에서 농도 의존적으로 장관 수축력을 증가시켰다. 혈압반응에서와 같이 장관실험에서도 두 약물에 의한 장관 수축력의 증가는 Atropine Sulfate(1$\times$$10^{-5}$ M)의 존재하에서는 완전히 차단되어졌다. 이상의 결과로부터 상엽 수층분획은 Acetylcholine과 유사한 작용을 지닌 물질을 함유하는 것으로 사료된다.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.357-366
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• 2004

We studied the effect of propofol (PPF) on the endothelium-dependent vascular responses in isolated rat thoracic aorta. In aortic rings with endothelium, PPF inhibited the phenylephrine (PE)-induced contraction in a concentration-dependent manner. In PE-precontracted preparations, PPF attenuated the endothelium-dependent relaxation by acetylcholine but not by A23187. And PPF did not attenuate the endothelium-independent relaxation by sodium nitroprusside (SNP). The relaxation induced by acetylcholine in PE-precontracted aortic rings was significantly augmented by zaprinast, a cGMP-specific phosphodiesterase inhibitor, and this augmentation was inhibited by PPF. Although SNP-induced relaxation was significantly augmented by zaprinast, this augmentation was not inhibited by PPF. In preparations preconstricted with PE, the PPF-induced relaxation was inhibited by atropine. In addition, PPF attenuated the vasorelaxation by phosphodiesterase inhibitors (IBMX, Ro20-1724 or zaprinast except milrinone). In vivo, the infusion of acetylcholine and SNP showed decreased arterial blood pressure in rats. The pre-injection of PPF inhibited the acetylcholine-induced blood pressure lowering, but not the SNP-induced blood pressure lowering. These results suggest that PPF can attenuate in part the acetylcholine-induced vasorelaxation and blood pressure lowering through the inhibition of the acetylcholine receptor-mediated endothelium-derived relaxing factor by acting on endothelium. It is considered that the inhibitory effect of PPF on the vasorelaxation is due to the decreased level of cGMP which can be attributed to the inhibition of the muscarinic receptor and/or receptor-G-protein interaction.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.347-355
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• 2004

This study was undertaken in order to evaluate effects of methanol extracts of Stachys sieboldii MIQ and its related enzyme activities in brain tissues of rats. Sprague-Dawley(SD) male rats were fed within a control group, which is a basic diet group. The experimental diet group was given 100 and 200 mg/kg to supervise 100 and 200 mg/kg body weight per day for 20 days. Lipid peroxide levels and acetylcholine esterase activity in brain tissues were slightly decreased at a dose dependent manner, in vitro. Lipid peroxide levels were also decreased at a dose dependent manner; methanolic extracts of Stachys sieboldii MIQ demonstrated significant inhibitory effects, in vivo. Monoamine oxidase and xanthine oxidase activities were significantly inhibited in the brain tissues of experimental group compared to control group and the ratio of type conversion of xanthine oxidase were decreased.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.493-500
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• 1994

The purpose of this study was to investigate the effects of neurotransmitters and the source of $Ca^{2+}$ in the effects of neurotransmitters on the motility of pig oviductal isthmic smooth muscle. The motility of the isolated smooth muscle was recorded by using physiological recording system. The results were summarized as follows; Acetylcholine, norepinephrine, histamine and prostaglandin $F_{2{\alpha}}(PGF_{2{\alpha}})$ caused the contraction and the contractile responses were increased in a dose-dependent manner from the concentration of $10^{-7}$ to $10^{-4}M$. The maximum contractility of acetylcholine, norepinephrine, histamine and $PGF_{2{\alpha}}$ was 65.99, 28.66, 83.99 and 47.33% of 100 mM K contraction, respectively. The contractile response induced by acetylcholine$(10^{-6}M)$ was completely blocked by the pretreatment with cholinergic receptor blocker, atropine$(10^{-6}M)$, the contractile response induced by norepinephrine$(10^{-5}M)$ was blocked by the pretreatment with ${\alpha}$-adrenergic receptor blocker, phentolamine$(10^{-6}M)$ but was not blocked and rather increased by the pretreatment with ${\beta}$-adrenergic receptor blocker. propranolol$(10^{-6}M)$, the contractile response induced by histamine$(10^{-6}M)$ was completely blocked by the pretreatment with $H_1$-histaminergic receptor blocker, pyrilamine$(10^{-6}M)$ but was increased by the pretreatment with $H_2$-histaminergic receptor blocker, cimetidine$(10^{-6}M)$. The contractile response induced by acetylcholine$(10^{-6}M)$, norepinephrine$(10^{-5}M)$ and histamine$(10^{-6}M)$ was weakly contracted response in $Ca^{2+}$-free medium, but the contractile response induced by $PGF_{2{\alpha}}(10^{-6}M)$ was disappeared. The contractile response induced by acetylcholine$(10^{-6}M)$, norepinephrine$(10^{-5}M)$ and histamine$(10^{-6}M)$ was powerfully depressed by the pretreatment with $Ca^{2+}$-channel blocker, verapamil$(10^{-5}M)$ but the contractile response induced by $PGF_{2{\alpha}}(10^{-6}M)$ was completely inhibited.

• Development and Reproduction
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• v.9 no.1
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• pp.7-13
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• 2005

The effects of various physicochemical stimuli in parturition induction were assayed on ovoviviparous freshwater melania snails, Semisulcospira libertina libertina and S. gottschei. Both of them did not respond to $NH_4OH$ and $H_2O_2$, but showed responses to the water temperature raising, serotonin and acetylcholine. S. gottschei showed stronger responses to the stimulants in parturition induction compared with S. libertina libertina. In case of S. libertina libertina exposed to $10^{-9}M$ acetylcholine, the number of newly born larvae and juveniles per adult and juvenile parturition rate were 68 individuals and 57.5%, which were the most among experimental groups, respectively. In the parturition induction with temperature raising of $9^{\circ}C$, S. gottschei bred 113 larvae and juveniles in which juvenile parturition rate was 56.3% and $10^{-12}M$ acetylcholine also induced very high juvenile parturition rate(61.7%) and 83 larvae and juveniles. It could be concluded that the treatment of acetylcholine has a high effectiveness in the parturition induction of S. libertina libertina and S. gottschei.