• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.116-122
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• 2001

Objectives : Schizophrenia manifests a variety of interindividual differences in therapeutic response to antipsychotics. This might be attributable to dopamine and serotonin receptors that a important target for various antipsychotics, and the $D_3$ receptor(DRD3) alleles they carry. The purpose of our study was to investigate whether the plasma levels of homovanillic acid(HVA) and 5-hydroxyindoleacetic acid(HIAA), and the polymorphism of DRD3 can be held as a predictor of treatment response in chronic schizophrenic patients. Methods : Therapeutic response for 116 korean schizophrenia patient treated during 48 weeks were assessed by PANSS used as the clinical symptom rating scales. The levels of concentration of HVA and 5-HIAA were examined by HPLC at baseline and at 48 weeks. We classified the polymorphism of DRD3 receptor using amplifying by polymerase chain reaction(PCR). Results : Neither concentrations of HVA and 5-HIAA nor genotype of dopamine 3 receptor were not significantly associated with the therapeutic response. But, the patients who has A1 alleles of DRD3 gene showed poor therapeutic responses. Conclusion : A1 allele of DRD3 gene is associated with poor prognosis of chronic schizophrenia.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.351-356
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• 2009

Many isoquinoline alkaloids including berberine lower dopamine content by reducing tyrosine hydroxylase (TH) activity and aggravate L-DOPA-induced cytotoxicity in PC12 cells. In this study, the effects of berberine on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in PC12 cells and on unilateral 6-OHDA-lesioned rat models were investigated. Berberine at 10-30 ${\mu}M$ did not affect cell viability in PC12 cells. However, berberine at concentrations higher than $50{\mu}M$ caused cytotoxicity at 24 h. Berberine (10-50 ${\mu}M$) also enhanced 6-OHDA (10-50 ${\mu}M$)-induced cytotoxicity at 24 h compared to 6-OHDA alone with an apoptotic process. In addition, treatment with berberine (5 and 30 mg/kg, i.p.) for three weeks showed a dopaminergic cell loss in substantia nigra of 6-OHDA-lesioned rats: 30 mg/kg berberine was more intensive cytotoxic. The levels of dopamine were also decreased by berberine (5 and 30 mg/kg) in the ipsilateral substantia nigra of 6-OHDA-lesioned rats. These results suggest that berberine aggravated 6-OHDA-induced cytotoxicity in PC12 cells and treatment with berberine (5 and 30 mg/kg) in 6-OHDA-lesioned rats also enhanced the degeneration of dopaminergic cell death and the decrease in dopamine levels in substantia nigra. Therefore, the long-term L-DOPA therapeutic patients with isoquinoline compounds including berberine may need to be checked for the adverse symptoms.

• Journal of Oriental Neuropsychiatry
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• v.14 no.1
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• pp.85-106
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• 2003

Studies have shown that both the psychomotor stimulant effects and rewarding properties of addictive drugs, including morphine, are sensitized by repeated drug administration and it is suggested that both of these effects are mediated by the same or closely overlapping dopamine systems. Specifically, the mesolimbic dopamine system has been implicated in the reinforcing and sensitizing properties of morphine. In oriental medicine, Shenmen (HT7) point on the heart channel has been used to treat mental and psychosomatic disorders. This study was designed to investigate the effect of acupuncture on acute and repeated morphine-induced changes in extracellular dopamine levels using in vivo microdialysis and morphine-induced behavioral changes. In the morphine sensitization experiment, male Sprague-Dawley rats were treated twice a day for three days with increasing doses of morphine (10, 20 and 40 mg/kg, s.c.) or with saline. After 15 days of withdrawal, rats were challenged with morphine hydrochloride (5mg/kg, s.c.). Acupuncture was applied at bilateral Shenmen (HT7) points for 1 min after the morphine challenge. In the acute experiment, rats also received acupuncture for 1 min after an injection of morphine hydrochloride (5 mg/kg, s.c.). Results showed that acupuncture at the specific acupoint HT7, but not at control points (tail) significantly decreased both dopamine release and behavior induced by a systemic morphine challenge or a single sc morphine injection in the acute animals. These results suggest that reduction in sensitization may be one mechanism whereby acupuncture alleviates morphine craving in addicts.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.510-517
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• 2003

Studies have shown that both the psychomotor stimulant effects and rewarding properties of addictive drugs, including morphine, are sensitized by repeated drug administration and it is suggested that both of these effects are mediated by the same or closely overlapping dopamine systems. Specifically, the mesolimbic dopamine system has been implicated in the reinforcing and sensitizing properties of morphine. In oriental medicine, Shenmen (HT7) point on the heart channel has been used to treat mental and psychosomatic disorders. This study was designed to investigate the effect of acupuncture on acute and repeated morphine-induced changes in extracellular dopamine levels using in vivo microdialysis and morphine-induced behavioral changes. In the morphine sensitization experiment, male Sprague-Dawley rats were treated twice a day for three days with increasing doses of morphine (10, 20 and 40 mg/kg, s.c.) or with saline. After 15 days of withdrawal, rats were challenged with morphine hydrochloride (5 mg/kg, s.c.). Acupuncture was applied at bilateral Shenmen (HT7) points for 1 min after the morphine challenge. In the acute experiment, rats also received acupuncture for 1 min after an injection of morphine hydrochloride (5 mg/kg, s.c.). Results showed that acupuncture at the specific acupoint HT7, but not at control points (tail) significantly decreased both dopamine release and behavior induced by a systemic morphine challenge or a single sc morphine injection in the acute animals. These results suggest that reduction in sensitization may be one mechanism whereby acupuncture alleviates morphine craving in addicts.

• Biomolecules & Therapeutics
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• v.30 no.1
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• pp.90-97
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• 2022

Recently, increasing evidence suggests that neuroinflammation may be a critical factor in the development of Parkinson's disease (PD) in addition to the ratio of acetylcholine/dopamine because dopaminergic neurons are particularly vulnerable to inflammatory attack. In this study, we investigated whether botulinum neurotoxin A (BoNT-A) was effective for the treatment of PD through its anti-neuroinflammatory effects and the modulation of acetylcholine and dopamine release. We found that BoNT-A ameliorated MPTP and 6-OHDA-induced PD progression, reduced acetylcholine release, levels of IL-1β, IL-6 and TNF-α as well as GFAP expression, but enhanced dopamine release and tyrosine hydroxylase expression. These results indicated that BoNT-A had beneficial effects on MPTP or 6-OHDA-induced PD-like behavior impairments via its anti-neuroinflammation properties, recovering dopamine, and reducing acetylcholine release.

• Nutrition Research and Practice
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• v.4 no.4
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• pp.270-275
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• 2010

Catecholamines are among the first molecules that displayed a kind of response to prolonged or repeated stress. It is well established that long-term stress leads to the induction of catecholamine biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine ${\beta}$-hydroxylase (DBH) in adrenal medulla. The aim of the present study was to evaluate the effects of ginseng on TH and DBH mRNA expression. Repeated (2 h daily, 14 days) immobilization stress resulted in a significant increase of TH and DBH mRNA levels in rat adrenal medulla. However, ginseng treatment reversed the stress-induced increase of TH and DBH mRNA expression in the immobilization-stressed rats. Nicotine as a ligand of the nicotinic acetylcholine receptor (nAChR) in adrenal medulla stimulates catecholamine secretion and activates TH and DBH gene expression. Nicotine treatment increased mRNA levels of TH and DBH by 3.3- and 3.1-fold in PC12 cells. The ginseng total saponin exhibited a significant reversal in the nicotine-induced increase of TH and DBH mRNA expression, decreasing the mRNA levels of TH and DBH by 57.2% and 48.9%, respectively in PC12 cells. In conclusion, immobilization stress induced catecholamine biosynthetic enzymes gene expression, while ginseng appeared to restore homeostasis via suppression of TH and DBH gene expression. In part, the regulatory activity in the TH and DBH gene expression of ginseng may account for the anti-stress action produced by ginseng.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.258-267
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• 2001

Purpose/Methods: Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum uslng $[^3H]$]WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Results: Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 mg/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4 mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. Conclusion: These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli.

• Korean Journal of Pharmacognosy
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• v.39 no.4
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• pp.341-346
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• 2008

The effects of the ethanol extracts from Gynostemma pentaphyllum (GP extracts) on body weights, grip strengths, endurances and catecholamine levels after electric footshock (EF) stress in mice and rats were investigated. The animals were treated with GP extracts (50 mg/kg/day, p.o.) for 21 days before exposure to EF (duration and interval 10 sec for 3 min, 2 mA) once a day. The increases in body weights were delayed by 13.1% of the control levels by EF-induced stress in mice, which were recovered to 24.1% of the control levels in GP extract-treated groups. The grip strengths were significantly decreased by EF stress in mice and the EF-stressed groups treated with GP extracts increased grip strengths to 115.2% compared to control levels. The endurance times by forced swimming, which reduced significantly by EF stress, were also maintained similar to control levels by GP extracts in rats. In addition, the levels of norepinephrine and epinephrine in serum and brain, and dopamine in brain were significantly increased to 17.5-95.0% of the control levels after exposure of EF stress in mice. However, EF stressinduced increases in norepinephrine and epinephrine in serum were reduced to 17.1-17.3% of the control levels by treatments of GP extracts, and those in dopamine, norepinephrine and epinephrine in brain were also reduced to 5.0-19.5%. These results suggest that GP extracts showed the protective effects on EF stress-induced physiological functions and can be developed as the promising anti-stress agents.

• Natural Product Sciences
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• v.19 no.4
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• pp.337-341
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• 2013

The effects of gypenosides (GPS) on electric footshock (EF)-induced acute stress in mice were investigated. Mice were treated orally with GPS (30-400 mg/kg) once a day for 5 days. After 2 days of GPS treatment, mice were exposed to EF stimuli (intensity, 2 mA; interval, 10 s; duration, 3 min) for acute stress for 3 days. Spontaneous locomotor activity was increased by acute EF stress, which was decreased by treatment with GPS (100 and 400 mg/kg). In addition, the increased levels of dopamine and serotonin by acute EF stress in the brain were reduced by treatment with GPS (100 and 400 mg/kg). The serum levels of corticosterone increased by acute EF stress were also reduced by GPS (100 and 400 mg/kg). These results suggest that GPS shows the ameliorating effects on acute EF stress by modulating the activity of dopaminergic and serotonergic neurons, and the serum levels of corticosterone. Clinical trials of GPS need to be conducted further so as to develop promising anti-stress agents.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.1-10
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• 2002

Objectives: Uncariae Ramulus Et Uncus extract is clinically used in Korea to treat ischemic cerebral damage. The present study was undertaken to study the neuroprotective effect of Uncariae Ramulus Et Uncus extract in middle cerebral artery occlusion (MCAO) rats. Methods: Changes of extracellular levels of dopamine, DOPAC, HVA. and HIAA in striatum were collected at 20 minutes interval by in vivo microdialysis and then analyzed by HPLC (high performance liquid chromatography) in rats subjected to permanent focal cerebral ischemia induced by 2 hours of MCAO. Uncariae Ramulus Et Uncus extract was orally administrated before MCAO. Different animals were used for measurement of cerebral infarction volume induced by 24 hours of MCAO with TIC staining and image analysis. Results: Extracellular levels of dopamine decreased after treatment with Uncariae Ramulus Et Uncus extract, while extracellular levels of DOPAC and HVA significantly increased. Cerebral infarction volume also significantly decreased after treatment with Uncariae Ramulus Et Uncus extract. Conclusions: These results provided evidence that Uncariae Ramulus Et Uncus extract can produce a neuroprotective effect on cerebral ischemia by regulating extracellular excitatory neurotransmitters.