• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.197-206
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• 2007

The aim of the present study was to investigate the effects of 6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine(SKF81297), a selective agonist of dopaminergic $D_1$ receptor, on the secretion of catecholamines(CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal gland, and also to elucidate the mechanism involved. SKF81297($10{\sim}100{\mu}M$) perfused into an adrenal vein for 60 min produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh(5.32 mM), high $K^+$(56 mM), DMPP($100{\mu}M$) and McN-A-343($100{\mu}M$). Also, in adrenal glands loaded with SKF81297($30{\mu}M$), the CA secretory responses evoked by Bay-K-8644($10{\mu}M$), an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid($10{\mu}M$), an inhibitor of cytoplasmic $Ca^{2+}$-ATPase were also inhibited. However, in the presence of the dopamine $D_1$ receptor antagonist, (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-benzazepine-7-ol(SCH23390, $3{\mu}M$), which is a selective antagonist of dopaminergic $D_1$ receptor, the inhibitory responses of SKF81297($30{\mu}M$) on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644, and cyclopiazonic acid were significantly reduced. Collectively, these experimental results suggest that SKF81297 inhibits the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation(both nicotininc and muscarinic receptors) and membrane depolarization. This inhibitory of SKF81297 seems to be mediated by stimulation of dopaminergic $D_1$ receptors located on the rat adrenomedullary chromaffin cells, which are relevant to extra- and intracellular calcium mobilization. Therefore, it is thought that the presence of the dopaminergic $D_1$ receptors may be involved in regulation of CA release in the rat adrenal medulla.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.32-42
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• 2009

The purpose of the present study was to examine the effect of dihydrexidine, a full $D_1$ receptor agonist, on the secretion of catecholamines (CA) from the perfused model of the rat adrenal gland, and to establish its mechanism of action. Dihydrexidine (10-100 ${\mu}M$), perfused into an adrenal vein for 60 min, relatively produced dose- and time-dependent inhibition in the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Dihydrexidine itself did fail to affect basal CA output. Also, in adrenal glands loaded with dihydrexidine (30 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$), an activator of L-type $Ca^{2+}$ channels, cyclopiazonic acid (10 ${\mu}M$), an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, and veratridine, an activator of voltage-dependent $Na+$ channels (10 ${\mu}M$), were also markedly inhibited, respectively. However, in the simultaneous presence of dihydrexidine (30 ${\mu}M$) and R (+)-SCH23390 (a selective antagonist of $D_1$ receptor, 3 ${\mu}M$), the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory responses by dihydrexidinetreatment alone. In conclusion, these experimental results suggest that dihydrexidine significantly inhibits the CA secretion evoked by cholinergic stimulation (both nicotinic and muscarinic receptors) and membrane depolarization from the rat adrenal medulla. It seems that this inhibitory effect of dihydrexidine may be mediated by inhibiting influx of both $Ca^{2+}$ and $Na^+$ into the cytoplasm as well as by suppression of $Ca^{2+}$ release from cytoplasmic calcium store through activation of dopaminergic $D_1$ receptors located on the rat adrenomedullary chromaffin cells.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.192-205
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• 2023

BACKGROUND/OBJECTIVES: It is known that the renin-angiotensin system (RAS) in the brain could regulate cognitive functions as well as blood pressure. Inhibition of RAS for the improvement of cognitive function may be a new strategy, but studies so far have mostly reported on the effects of RAS inhibition by drugs, and there is no research on cognitive improvement through RAS inhibition of food ingredients. Therefore, this study investigated the effect of curcumin on blood pressure and cognitive function and its related mechanism in spontaneously hypertensive rat/Izm (SHR/Izm). MATERIALS/METHODS: Six-week-old SHR/Izm rats were divided into 5 groups: control group (CON), scopolamine group (SCO, drug for inducing cognitive deficits), positive control (SCO and tacrine [TAC]), curcumin 100 group (CUR100, SCO + Cur 100 mg/kg), and curcumin 200 group (CUR200, SCO + Cur 200 mg/kg). Changes in blood pressure, RAS, cholinergic system, and cognitive function were compared before and after cognitive impairment. RESULTS: The SCO group showed increased blood pressure and significantly reduced cognitive function based on the y-maze and passive avoidance test. Curcumin treatments significantly improved blood pressure and cognitive function compared with the SCO group. In both the CUR100 and CUR200 groups, the mRNA expressions of angiotensin-converting enzyme (ACE) and angiotensin II receptor type1 (AT1), as well as the concentrations of angiotensin II (Ang II) in brain tissue were significantly decreased. The mRNA expression of the muscarinic acetylcholine receptors (mAChRs) and acetylcholine (ACh) content was significantly increased, compared with the SCO group. CONCLUSIONS: The administration of curcumin improved blood pressure and cognitive function in SCO-induced hypertensive mice, indicating that the cholinergic system was improved by suppressing RAS and AT1 receptor expression and increasing the mAChR expression.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2997-3002
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• 2011

A series of hybrid molecules between (R)-lipoic acid (ALA) and the acetylated or methylated polyphenol compounds were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were checked. The $IC_{50}$ values of all hybrid molecules for a BuChE inhibition were lower than those of the single parent compounds. Specifically, ALA-acetyl protected caffeic acid (11, ALA-AcCA) was shown as an effective inhibitor of BuChE ($IC_{50}=0.5{\pm}0.2\;{\mu}M$) and also had a great selectivity for BuChE over AChE (more than 800 fold). Inhibition kinetic study indicated that 11 is a mixed inhibition type. Its binding affinity ($K_i$) value to BuChE is $1.52{\pm}0.18\;{\mu}M$.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.307-314
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• 1999

The human muscarinic acetylcholine receptor (mAChR) subtypes Hml, Hm2 and Hm3 have been expressed in insect cells (Spodoptera frugiperda, Sf9) using the baculovirus expression system. Expression of relevant DNA, transcript and receptor proteins was identified by PCR, Northern blotting and [$^{3}H$]QNB binding, respectively. As assessed by [$^{3}H$]QNB binding sites, yields of muscarinic receptors in membrane preparations in this study were as about 5-20 times high as those in mammalian cells reported in previous studies. The [$^{3}H$]QNB competition binding studies with well-known subtype-selective mAChR antagonists showed that the receptors expressed in Sf9 cells retain the pharmacological characteristics expected for the ml , m2 and m3 muscarinic receptors. The ml-selective antagonist, pirenzepine, displayed a considerably higher affinity for Hml by 110-fold and 35-fold than for Hm2 and Hm3, respectively, The m2-selective methoctramine displayed a significantly higher affinity for Hm2 than for Hml and Hm3 (10- and 26-fold, respectively). p-F-HHSiD exhibited high affinity for Hm3 that is not significantly different from those for Hml, but 66-fold higher than its affinity for Hm2. The functional coupling of the recombinant receptors to second messenger systems was also examined. While both Hml and Hm3 stimulated phosphoinositide hydrolysis upon activation by carba-chol, Hm2 produced no response. On the other hand, activation of mAChRs induced the inhibition of forsko-lin-stimulated cyclic AMP formation in Hm2-expressing cells, whereas the significant dose-dependent increase in or poor response on cyclic AMP formation were produced in Hml or Hm3-expressing cells, respectively. These results indicate the differential coupling of recombinant Hml, Hm2 and Hm3 receptors expressed in SF9 cells to intracellular signalling system.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.268.2-268.2
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• 2001

• The Korean Journal of Mycology
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• v.47 no.1
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• pp.75-81
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• 2019

The goal of this study was to characterize unrecorded wild yeasts from soils of spices plants fields and further, to elucidate its anti-demential activities and tyrosinase inhibitory activity. Piskurozyma taiwanensis R4-1 (NIBRFGC000502619), Nadsonia starkeyi-henricii R6-2 (NIBRFGC000502618), and Canadida friedrichii M12-6 (NIBRFGC000502615) isolated from soil of garlic field represented newly recorded yeast strains in Korea. Vishniacozyma peneaus I2-9 (NIBRFGC000502617) and Cryptococcus aspenensis I21-1 (NIBRFGC000502616) from soil of ginger field represented also newly recorded yeast strains, and microbiological characteristics of its fifteen yeast strains were investigated. All of these unrecorded yeasts exhibited oval-global shape and have ascospores except Canadida friedrichii M12-6. Piskurozyma taiwanensis R4-1 and Canadida friedrichii M12-6 grew well in vitamin-free medium, and Piskurozyma taiwanensis R4-1 was halotolent growing in 10% NaCl-containing yeast extract peptone dextrose (YPD) broth. After prepared cell-free of the unrecorded wild yeasts, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities as anti-dementia activity and tyrosinase inhibitory activity as whitening activity were determined. Cell-free extract from Canadida friedrichii M12-6 had the highest tyrosinase inhibitory activity of 14.4%.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1666-1685
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• 2004

This present study was designed to screen medicinal plants for the treatment of brain diseases such as Parkinson's disease or aging. We tested the effects of the water extracts from 38 species medicinal plants on antioxidant capacity, monoamine oxidase B (MAO-B) inhibitory activity, acetylcholinesterase (AChE) inhibition and antiperoxidation activity in vitro. The water extracts from 38 species were tested on their antioxidant activity using radical scavenging effects against ABTS+. The water extract of C. sappan was showed the highest antioxidant capacity, the antioxidant activity at 1 Jig of herbal extract being 0.38mM TE. Lipid peroxidation in brain homogenates induced by NADPH and ADP-Fe/sup 2+/ was strong inhibited by C. sappan and R. palmatum extracts. Among the 38 medicinal plants investigated, R. palmatum showed significant biological activity (antioxidant capacity, MAO-B inhibiory activity, and AChE inhibitory activity). The protective efficacy of R. palmatum water extract on 1-methyl-4­phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism and its possible mechanism were studied in C57BL/6 mice. Treatment of R. palmatum water extract protected biomacromolecules such as lipids from oxidative damage induced by MPTP. The content of MDA in brain tissue was decreased significantly by R. palmatum extract. These results suggest that R. palmatum water extract plays on effective role in attenuating MPTP-induced neurotoxicity in mice. This protective effect of R. palmatum might be estimated the result from the inhibitory activity on monoamine oxidase B and the enhancement of antioxidant activity.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.145-152
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• 2001

The purpose of this study was to determine nitrogen dioxide(NO$_2$) decay rate by reaction between NO$_2$ and interior materials in Korean residence. The results of this research could be helpful to choose the interior construction materials and to study on reduction of indoor air pollutants. The results of this research are as follows; For 30 residences in Seoul and Incheon from October 2000 to march 2001, the mean of infiltration rate was 0.70$\pm$0.44 ACH, and single-detached houses (7 houses) and apartments (19 houses) were 0.97$\pm$0.55 ACH and 0.61$\pm$0.34 ACH, respectively. The $CO_2$ decay followed approximately first-order process ($R^2$=0.97$\pm$0.02). There existed a statistic significance in filtration rate between houses built in 1980’s and built in 1990’s by t-test (p<0.02). Mean of NO$_2$ decay rates in 26 residence3s except 4 residences was 0.94$\pm$0.49hr$^{-1}$ , and also 0.86$\pm$0.49hr$^{-1}$ , 0.97$\pm$0.50hr$^{-1}$ in single-detached houses and apartments, respectively. Mean NO$_2$ decay rates in houses built in 1980’s were 0.78$\pm$0.37hr$^{-1}$ , 1.33$\pm$1.03hr$^{-1}$ , respectively. Nothing were showed statistical significance among indoor temperature, indoor humidity, and NO$_2$ decay rate. However, NO$_2$ decay rates had a tendency to increase by increase of temperature and humidity. Average volume/surface of participated houses was 0.55$\pm$0.07m and mean NO$_2$ deposition velocity was calculated as 1.46$\pm$0.59msec$^{-1}$ .

• 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.