• Biomolecules & Therapeutics
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• v.25 no.2
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• pp.112-121
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• 2017

Drug-induced liver injury (DILI) is the serious and fatal drug-associated adverse effect, but its incidence is very low and individual variation in severity is substantial. Acetaminophen (APAP)-induced liver injury accounts for >50% of reported DILI cases but little is known for the cause of individual variations in the severity. Intrinsic genetic variation is considered a key element but the identity of the genes was not well-established. Here, pre-biopsy method and microarray technique was applied to uncover the key genes for APAP-induced liver injury in mice, and a cause and effect experiment employing quantitative real-time PCR was conducted to confirm the correlation between the uncovered genes and APAP-induced hepatotoxicity. We identified the innately and differentially expressed genes of mice susceptible to APAP-induced hepatotoxicity in the pre-biopsied liver tissue before APAP treatment through microarray analysis of the global gene expression profiles (Affymetrix $GeneChip^{(R)}$ Mouse Gene 1.0 ST for 28,853 genes). Expression of 16 genes including Gdap10, Lpl, Gabra3 and Ccrn4l were significantly different (t-test: FDR <10%) more than 1.5 fold in the susceptible animals than resistant. To confirm the association with the susceptibility to APAP-induced hepatotoxicity, another set of animals were measured for the expression level of selected 4 genes (higher two and lower two genes) in the liver pre-biopsy and their sensitivity to APAP-induced hepatotoxicity was evaluated by post hoc. Notably, the expressions of Gabra3 and Lpl were significantly correlated with the severity of liver injury (p<0.05) demonstrating that these genes may be linked to the susceptibility to APAP-induced hepatotoxicity.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.23-29
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• 1998

Background: The present study was conducted to investigate effects of microinjection of bicuculline, GABA-A receptor antagonist, into the brain stem nuclei on the dorsal horn neuron responsiveness in rats with an experimental peripheral neuropathy. Methods: An experimental neuropathy was induced by a unilateral ligation of L5~L6 spinal nerves of rats. After 2~3 weeks after the surgery, single-unit recording was made from wide dynamic range (WDR) neurons in the spinal cord dorsal horn. Results: Responses of WDR neurons to both noxious and innocuous mechanical stimuli applied to the somatic receptive fields were enhanced on the nerve injured side. These enhanced responsiveness of WDR neurons were suppressed by microinjection of bicuculline into periaqueductal gray(PAG) or nucleus reticularis gigantocellularis(Gi). A similar suppression was also observed when morphine was microinjected into PAG or Gi. Suppressive action by Gi-bicuculline was reversed by naloxonazine, ${\mu}$-opioid receptor antagonist, microinjected into PAG whereas PAG-bicuculline induced suppression was not affected by naloxonazine injection into Gi. Gi-bicuculline induced suppression were reversed by a transection of dorsolateral funiculus(DLF) of the spinal cord. Conclusions: The results suggest that endogenous opioids, via acting on GABAergic interneurons in PAG and Gi, may be involved in the control of neuropathic pain by activating the descending inhibitory pathways that project to the spinal dorsal horn through DLF to inhibit the responsiveness of WDR neurons.

• Journal of Ginseng Research
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• v.24 no.3
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• pp.134-137
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• 2000

Spontaneous bursting activity was studied in rat thalamocortical slices using extracellular field potential recording to test the potential utilization of ginsenoside Rb$_1$ in controlling overactivated neural systems. In order to induce bursting activity, slices were perfused with Mg$\^$2+/-free artificial cerebrospinal fluid (ACSF). Two major types of spontaneous bursting activity, simple thalamocortical burst complexes (sTBCs) and complex thalamocortical burst complexes (cTBCs), were recorded in Mg$\^$2+/ -free ACSF. Ginsenoside Rb$_1$ selectively suppressed cTBCs. Duration and occurrence rate of cTBCs were reduced by 87.3${\pm}$10.2% and 85.3${\pm}$ 14.7% in the presence of 90 ${\mu}$M ginsenoside Rb$_1$ respectively, while amplitude and intraburst frequency were slightly changed by ginsenoside Rb$_1$. In contrast, ginsenoside Rb$_1$was much less effective in reducing duration and occurrence rate of sTBCs. We also tested effects of ginsenoside Rb$_1$ on bursting activity in the presence of a GABA$\sub$A/ receptor antagonist, bicuculline methiodide (BMI). Ginsenoside Rb$_1$ had no effect in suppressing BMI-induced bursting activities. These results suggest that ginsenoside Rbi may be useful in controlling seizure-like bursting activity under pathological conditions.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.2
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• pp.33-42
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• 2011

Zinc plays a key role in genetic expression, cell division, and cell growth and is essential for the functions of more than 450 metalloenzyme. There are high concentrations of zinc in pigment epithelium in bullfrog eye. Zinc deficiency causes night blindness and abnormal dark adaptation. The purpose of this study was to identify ERG (electroretinogram) b-wave sensitivity during light and dark adaptation in bullfrog retina after zinc and zinc chelators treatment such as histidine and TSQ (N-(6-methoxy-8-qunolyl)-p-toluenesulfon amide). Especially, we focused whether histidine act as a zinc chelator in the Muller cell. The results of our study are summarized as follows: 1) Both zinc and histidine elevated ERG b-wave amplitude and threshold in Muller cells by accelerating rhodopsin regeneration time and increased a-peak absorbance during light adaptation. 2) TSQ reduced those by prolonging rhodopsin regeneration time and decrement of a-peak absorbance during light adaptation. 3) Zinc shortened rhodopsin regeneration time and prolonged a-peak absorbance. These results suggested that histidine may act as a zinc-mediated transporter in presynaptic Muller cell membrane rather than zinc chelator and acts as a GABA-receptor inhibitor which blocks $Cl^-$ influx to the postsynapse.

• Korean Journal of Biological Psychiatry
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• v.20 no.4
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• pp.129-135
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• 2013

Aggression can be defined as 'behavior intended to harm another' which can be seen both from humans and animals. However, trying to understand aggression in a simplistic view may make it difficult to develop an integrated approach. So, we tried to explain aggression in a multidisciplinary approach, affected by various factors such as neuroanatomical structures, neurotransmitter, genes, and sex hormone. Parallel with animal models, human aggression can be understood with two phenomena, offensive aggression and defensive aggression. Neurobiological model of aggression give a chance to explain aggression with an imbalance between prefrontal regulatory influences and hyper-reactivity of the subcortical areas involved in affective evaluation, finally in an aspect of brain organization. Serotonin and GABA usually inhibit aggression and norepinephrine while glutamate and dopamine precipitate aggressive behavior. As there is no one gene which has been identified as a cause of aggression, functions between gene to gene interaction and gene to environment interaction are being magnified. Contributions of sex hormone to aggression, especially molecular biologic interaction of testosterone and regulation of estrogen receptor have been emphasized during the research on aggression. This multidisciplinary approach on aggression with types, neurochemical bases, and animal models can bring integrated interpretation on aggression.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.13-17
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• 2006

Experimentally induced cortical disorganization exhibits many anatomical features which are characteristic of cortical malformations in children with early-onset epilepsy. We used an immunocytochemical technique and extracellular field potential recordings from the dorsal hippocampus to determine whether the excitability of the CA1 pyramidal cells was enhanced in rats with exnerimentallv induced hippocampal dysplasia. Compared with control rats, the MAM-treated rats displayed a decrease of paired pulse inhibition. When $GABA_A$ receptor antagonists were blocked with $10{\mu}M$ bicuculline the amplitude of the second population spike of the MAM-treated of rats was similar to that of the first population spike, as was in the control rats. The MAM-treated rats had fewer somatostatin and parvalbumin-immunoreactive neurons than the control rats. These results suggest that the enhanced neuronal responsiveness of the in vivo recording of the CA1 in this animal model may involve a reduction of CA1 inhibition.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.217-221
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• 2007

Ginseng has been widely used for the management of anxiety and emotional instability, but there is little experimental evidence supporting these clinical applications. The anxiolytic-like effect of ginseng saponin and polysaccharide fractions of white (WG) and red ginsengs (RG) was investigated using the elevated plus-maze test. The saponin (SF) and polysaccharide (PF) fractions were orally administered to male ICR mice for 3 days and behavioral test for the anxiolytic activity were performed. SF significantly increased the time-spent open arms and number into the in the open arm entries. However, PF weakly increased the time-spent in the open arms, but did not increase number into the open ann entries. The WG showed more potent anxiolytic-like effect than that of RG. The anxiolytic-like activities were antagonized by flumazenil, but not by esmolol. These findings suggest the saponin fractions of WG and RG promote the anxiolytic-like activity by antagonizing GABN/benzodiazepine receptors in mice.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.135-141
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• 2009

The purpose of this study was to characterize the putative anxiolytic-like effects of the 70% ethanol extract of Portulaca oleracea (EPO) using an elevated plus maze (EPM) in mice. The EPO was orally administered at 50, 100, 200 or 400 mg/kg to ICR mice, 1 h before the behavioral evaluation in the EPM, respectively. Control mice were treated with an equal volume of 10% tween 80, and positive control mice with diazepam (1 mg/kg). Single treatments of the EPO significantly increased the percentage of time spent and arm entries into the open arms of the EPM versus controls (P < 0.05). Moreover, there were no changes in the locomotor activity and myorelaxant effects in any group compared with the saline controls. In addition, the anxiolytic-like effects of the EPO were blocked by flumazenil (10 mg/kg, i.p), a $GABA_A$ antagonist not by WAY 100635 (0.3 mg/kg, i.p), a 5-$HT_{1A}$ receptor antagonist. These results indicate that P. oleracea is an effective anxiolytic agent, and suggest that the anxiolytic-like effects of P. oleracea is mediated via the GABAergic nervous system.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.242-248
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• 1999

Diazepam, a benzodiazepine (BDZ) agonist, produces sedation and flumazenil, a BDZ antagonist, blocks these actions. The aim of this study was to examine the effects of BDZs on cortical electroencephalogram (EEG) in rats. The recording electrodes were implanted over the frontal and parietal cortices bilaterally, and the reference and ground electrodes over cerebellum under ketamine anesthesia. To assess the effects of diazepam and flumazenil, rats were injected with diazepam (1 mgHg, i.p.) and/or flumazenil ( 1 mg/kg, i.p.), and the EEG was recorded before and after drugs. Normal awake had theta peak in the spectrum and low amplitude waves, while normal sleep showed large amplitude of slow waves. The powers of delta, theta and alpha bands were increased during sleep compared with during awake. Diazepam reduced the mobility of the rat and induced sleep with intermittent fast spindles and large amplitude of slow activity, and it produced broad peak over betaL band and increased the power of gamma band, which were different from EEG patterns in normal sleep. Saline injection awakened rats and abolished fast spindles for a short period about 2-5 min from EEG pattern during diazepam-induced sleep. Flumazenil blocked both diazepam-induced sleep and decreased the slow activities of delta, theta, alpha and betaL, but not of gamma activity for about 10 min or more. This study may indicate that decrease in power of betaL and betaH bands can be used as the measure of central action of benzodiazepines, and that the EEG parameters of benzodiazepines have to be measured without control over the behavioral state by experimenter.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.102-107
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• 1997

Ginseng root, as a folk medicine, has been used in far eastern countries for thousands of years. Ginseng extract has been shown to have a variety of effects on the activity of the central nervous system, promoting stimulation as well as inhibition of the cortical activity. A survey of the relevant literatures has indicated that the putative anxiolytic activity of red ginseng has not been scientifically investigated. Therefore, the present study was designed to assess anxiolytic effect of gingseng total saponins(GTS). The putative anxiolytic effects of several fractions of GTS were investigated in mice using an elevated plus maze paradigm. Single dose administration of TS Fr.-I showed anxiolytic action in mice. Anxiolytic effect induced by TS Fr.-I was similar to that induced by diazepam. TS Fr.-II, TS Fr.-III and TS Fr.-IV did not show the anxiolytic action compared with that of TS Fr.-I. It was suggested that regulation of GABAergic neurotransmission may be important in the action of GTS. The Interaction of GTS fractions with benzodiazepine receptor was performed using rat cortical membranes. GTS inhibited the binding of [3H] Ro 15-1788 on the benzodiazepine receptor. Among from TS fractions, the binding activity of GTS in the TS Fr.-IV was highest, which did not show the anxiolytic activity. From these results, we conclude that GTS has anxiolytic action, and this is not related to benzodiazepine receptor binding activity.