• The Korean Journal of Pharmacology
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• v.17 no.2
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• pp.7-16
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• 1981

Higenamine ($Ca_{26}H_{17}No_3$. HCI, d1-1- (4-hydroxybenzyl) -6,7-dihydroxy-1,2,3,4-tetrahydroiso-quinoline hydrochloride), which has recently teen isolated from the Aconite root, was known to the cardiotonic component of the Aconite root. The positive inotropic effect of Higenamine was observed in the isolated electrically driven left atrium from rabbits with respect to the influences of extracellular calcium and of calcium antagonists, e.g. $La^{+++}$ and verapamil. A synergistic relation in the positive inotropic effect could be demonstrated between Higenamine and extra cellular calcium. The inotropic potency of $10^{-7}\;g/ml$ Higenamine was equivalant to that of 0.058 mM of calcium in the medium. In the preparation, of which contractility had been reduced by the treatment of $La^{+++}(10^{-5}-10^{-4}M)$ and verapamil$(2{\times}10^{-7}-10^{-6}M)$, Higenamine was able to restore the contractility. These results indicated that one of the possible mechanism of positive inotropism of Higenamine was to accelerate the influx of calcium from the extracellular space through the sarcolemma.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.359-381
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• 1992

This study was designed to investigate the effect of diazepam on the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus. Female rat(Sprague-Dawley) pretreated with oophorectomy and 4 days administration of estrogen, weighing about 200 g, was sacrificed by cervical dislocation, and the uteruses were isolated. A longitudinal muscle strip was placed in temperature controlled($37^{\circ}C$) muscle chamber containing Locke's solution and myographied isometrically. Diazepam inhibited the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus in a concentration-dependent manner. GABA, muscimol, a GABA A receptor agonist, bicuculline, a competitive GAGA A receptor antagonist, picrotoxin, a non competitive GABA A receptor antagonist, baclofen, a GABA B receptor agonist, and delta-aminovaleric acid, a GABA B receptor antagonist, did not affect on the spontaneous and oxytocin induced contraction of the isolated rat uterus. The inhibitory actions of diazepam on the spontaneous and oxytocin induced contraction were not affected by all the GABA receptor agonists and antagonists, but exceptionally potentiated by bicuculline. This potentiation-effect by bicuculline was not antagonized by muscimol. In normal calcium PSS, addition of calcium restored the spontaneous contraction preinhibited by diazepam and recovered the contractile of oxytocin preinhibited by diazepam. A23187, a calcium inophore, enhanced the restoration of both the spontaneous and oxytocin induced contraction by addition of calcium. In calcium-free PSS, diazepam suppressed the restoration of spontaneous motility by addition of calcium but allowed the recovery of spontaneous motility to a considerable extent. Diazepam could not inhibit some development of contractility by oxytocin in calcium-free PSS, but inhibited the increase in contractility by subsequent addition of calcium. These results suggest that the inhibitory action of diazepam on the rat uterine motility does not depend on or related to GABA receptors and that diazepam inhibits the extracellular calcium influx to suppress the spontaneous and oxytocin induced contractilities.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.119-124
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• 1988

The desmutagenic effects of ${\alpha}$-hydroxycarbonyl compounds, such as glyceraldehyde, glycolaldehyde, dihydroxyacetone, furfural, 5-hydroxymethylfurfural, maltol, acetol and acetoin and ${\alpha}$-dicarbonyls, such as diacetyl, glyoxal, methyl glyoxal and 2, 3-pentanedione were investigated against the mutagenic heterocyclic amines, such as Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 and IQ. Most of the carbonyl compounds suppressed the mutagenicity of heterocyclic amines for S. typhimurium TA98, ${\alpha}$-dicarbonyl compounds showing a higher desmutagenic effect than ${\alpha}$-hydroxycarbonyl compounds. Among the ${\alpha}$-hydroxycarbonyl compounds, glyceraldehyde, glycolaldehyde and dihy-droxyacetone showed more effective desmutagenicity, and diacetyl among the ${\alpha}$-dicabonyl compounds had the highest desmutagenic effect. These carbonyl compounds alone also showed mutagenicity to S. typhimurium TA100 without S-9 mix. The reaction of carbonyl compounds with mutagenic heterocyclic amines also eliminated the mutagenicity of the former for S. typhimurium TA100.

• Korean Journal of Clinical Pharmacy
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• v.21 no.2
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• pp.115-121
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• 2011

에토포시드와 아피제닌의 약동학적 상호작용 연구를 위하여 아피제닌 (0.4, 2.0 또는 8 mg/kg)과 에토포시드의 경구(6 mg/kg) 및 정맥 (2 mg/kg) 투여 하여 본 연구를 실시하였다. 아피제닌이 cytochrome P450 (CYP) 3A4 활성과 P-glycoprotein (P-gp)의 활성에 미치는 영향도 평가하였다. 아피제닌의 CYP3A4의 50% 효소활성억제는 $1.8{\mu}M$ 이었다. 아피제닌은 MCF-7/ADR 세포의 로다마인-123 세포 축적을 증가 시키므로 P-gp를 억제시켰다. 아피제닌은 에토포시드의 혈장곡선하면적과 최고혈장농도 (AUC and $C_{max}$)를 유의성 있게 증가시켰으나, 에토포시드의 최고혈장농도 도달시간 ($T_{max}$)과 생물학적 반감기 ($t_{1/2}$)에는 영향을 미치지 않았다. 따라서, 아피제닌 존재하에 에토포시드의 절대적생체이용률 (AB)은 대조군과 비교하여 유의성있게 증가되었다. 경구투여시와는 대조적으로, 아피제닌은 정맥 내로 투여된 에토포시드에서는 약동학적 파라미터에 어떤 영향도 미치지 않았다. 따라서 아피제닌이 에토포시드의 생체이용률을 증가시킨 것은 아피제닌이 소장과 간장에서 CYP3A4을 억제 및 소장에서 P-gp를 억제 시켰기 때문으로 사료된다.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.1-9
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• 2003

To reduce the possibility of longitudinal dynamic instability, called "POGO", in the liquid rocket system due to the feedback effect of a main structure and a fuel-feeding system, several different types of PSD(POGO Suppression Device) systems have been studied. In the present study, several different types of PSD were reviewed. Basically, all PSD systems can be categorized into two groups; a passive PSD or an active PSD. We can classify the passive PSD's into more detailed groups according to their compliance methods; localized compliance methods or distributed compliance methods. As a result of our intensive review on various PSD's, the gas-filled accumulator with a level control system is considered to be the most suitable one to suppress the POGO instability without mal-effects to the performance of a fuel-feeding system.ng system.

• The Korean Journal of Pharmacology
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• v.28 no.2
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• pp.171-179
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• 1992

Effects of a $M_1$ receptor antagonist, pirenzepine, a $M_2$ receptor antagonist, AF-DX116, and a nicotinic receptor antagonist, mecamylamine on the pressor responses to preganglionic sympathetic nerve stimulation (PNS) and McN-A-343 and DMPP in spinal (pithed) rabbits were investigated, in order to elucidate a functional role of $M_1$, $M_2$ and nicotinic receptors in ganglionic transmission. Pirenzepine and AF-DX116 selectively inhibited the McN-A-343-induced pressor response in chlorisondamine-treated rabbit and the BCh-induced bradycardia, respectively. Electrical stimulations of preganglionic sympathetic outflow at T8 level produced increases in blood pressure. Pirenzepine $(3\;{\mu}g/kg)$ significantly inhibited the PNS-induced pressor response and the degree of inhibition was not changed by increasing the doses to $100\;{\mu}g/kg$. AF-DX116 $(100\;{\mu}g/kg)$ had no effect on the PNS-induced pressor response. Mecamylamine inhibited the PNS-induced pressor response in a dose-dependent manner. The inhibitory action of mecamylamine was significantly augmented by combined-treatment with pirenzepine $(30\;{\mu}g/kg)$ but AF-DX116 $(100\;{\mu}g/kg)$ did not affect the inhibitory action of mecamylamine. McN-A-343 and DMPP elicited pressor response in the spinal rabbit. Pirenzepine and AF-DX116 dose-dependently inhibited the McN-A-343-induced pressor response but they did not affect DMPP-induced pressor response. Mecamylamine inhibited both pressor responses induced by McN-A-343 and DMPP. These results suggest that not only nicotinic receptors but also $M_1$ receptors play a facilitatory role in ganglionic transmission but $M_2$ receptors do not contribute the transmission in spinal (pithed) rabbits.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.511-534
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• 2015

The primary goal of the present study was to examine the moderating effects of coping strategies, cultural identity, and bicultural self-efficacy on the relationship between perceived discrimination and depressive symptoms of Korean Canadian college students. Data were collected from 214 Korean Canadian college students studying in Canada through an online and offline survey. A direct effect of perceived discrimination on depressive symptoms and the moderating effects of coping strategies on the relationship between perceived discrimination and depressive symptoms were examined by using hierarchical regression analysis. And three-way interaction of perceived discrimination, coping strategies, and cultural identity, and perceived discrimination, coping strategies, and bicultural self-efficacy on depressive symptoms were examined. Results from a hierarchical regression indicated that perceived discrimination significantly predicted depressive symptoms and this finding is in line with previous studies. Second, reflective, suppressive, and reactive coping strategies did not moderate the relationship between perceived discrimination and depressive symptoms. Third, the three-way interaction effect of perceived discrimination, suppressive coping strategy, and heritage identity predicted the depressive symptoms. Low heritage identity, high level of perceived discrimination and the frequent use of suppressive coping strategy increased the level of depressive symptoms. Fourth, the three-way interaction effect of perceived discrimination, coping strategies, and bicultural self-efficacy did not predict the depressive symptoms. Limitations and applied implications of the results are discussed.

• The Korean Journal of Pharmacology
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• v.29 no.2
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• pp.245-252
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• 1993

Amiloride is a potassium sparing duretic which specifically inhibits $Na{^+}$ channels. In the present study, we investigated the possible interaction of amiloride with $A_1$ adenosine receptors-adenylyl cyclase system in crude adipocytic plasma membrane fractions prepared from Sprague-Dawley rats. When the function of $G_i$ protein (inhibitory guanine nucleotide binding protein) was assessed by determining the effects of GTP on isoproterenol-stimulated adenylyl cyclase activity, the inhibitory effect of high concentrations of GTP was not observed in the presence of amiloride. In contrast, the adenosine receptor-mediated inhibition of the enzyme activity, as determined empolying 2-chloroadenosine, was either unchanged or even more enhanced by amiloride depending on the concentrations of 2-chloroadenosine. Thus, it appears that GTP- and receptor-mediated inhibitory function of $G_{i}$ proteins can be separated from one another. Receptor-mediated function of $G_{s}$ protein did not appear to be significantly affected by amiloride, since the inhibition of isoproterenol-stimulated adenylyl cyclase activity by propranolol under the same conditions was not significantly altered by amiloride. The enhancement of 2-chloroadenosine-mediated inhibition of adenylyl cyclase by amiloride was maintained in the presence of 150 mM NaCl. In summary, these results suggest that amiloride interacts both with $A_{l}$ adenosine receptors and with $G_i$ proteins in adipocytic membranes. Its binding to the $A_1$ adenosine receptors appears to facilitate the coupling of the receptors with $G_i$ proteins thereby enhancing the inhibition of isoproterenol-stimulated adenylyl cyclase activity by $A_1$ adenosine agonist, and the direct interaction with $G_i$ proteins appears to remove the GTP-dependent inhibitory effect on adenylyl cyclase activity.

• Science of Emotion and Sensibility
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• v.24 no.1
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• pp.3-10
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• 2021

This study examined the effect of intentional thought avoidance(i.e., thought suppression and thought substitution) using "Think and No Think" task. Two syllable words were selected, and recall test was performed with a single subject group. recall accuracy of them was measured in two recall conditions(cue recall and target recall) and four training conditions(thought, thought suppression, thought substitution, and baseline). The results showed that recall accuracy in cue recall condition was better than in target recall condition, regardless of training conditions, and recall accuracy in thought condition was better than in other training conditions, regardless of recall conditions. Also there was significant interaction between recall and training conditions: For thought suppression. there was no difference between two recall conditions, whereas for thought substitution, recall accuracy in cue recall condition was better than in target condition. These findings indicate that thought avoidance strategies, including both thought suppression and thought substitution, are effective in avoiding the specific thought intentionally, and thought suppression and thought substitution could be applied by different mechanism.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.264-270
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• 2017

Brassinosteroid (BR), a plant steroid hormone, plays a critical role in the growth and developmental processes through its canonical signaling and crosstalk with various internal and external signaling pathways. Recent studies have revealed the essential interplay mechanisms between BR and ABA during seed germination and early seedling establishment. However, molecular mechanisms for this important signaling crosstalk are largely unknown. To understand the crosstalk between BR-mediated signaling pathways and ABA functions during early seedling development, we carried out a comparative genome-wide transcriptome analysis with an Agilent Arabidopsis $4{\times}44K$ oligo chip. We selected and compared the expression patterns of ABA response genes in ABA-insensitive bes1-D mutant with wild type seedlings on which ABA was exogenously applied. As a result, we identified 2,353 significant differentially expressed genes (DEGs) in ABA-treated bes1-D and wild type seedlings. GO enrichment analysis revealed that ABA signaling, response, and metabolism were critically down-regulated by BR-activated signaling pathways. In addition, the genome-wide transcriptome analysis data revealed that BR-regulated signaling pathways were tightly connected to diverse signal cues including abiotic/biotic stress, auxin, ROS etc. In this study, we newly identified the molecular mechanisms of BR-mediated repression of ABA signaling outputs. Also, our data suggest that interplay among diverse signaling pathways is critical for the adaptive response of the plant to various environmental factors.