Effects and significance of α-synuclein on β-arrestin 2 expression in Parkinson' disease in a mouse model / 中华老年医学杂志

Objective:To investigate the effects and significance of α-synuclein(α-syn)on the expression level of β-arrestin 2 in Parkinson's disease(PD)in a mouse model.Methods:Twenty-eight C57BL/6J mice with similar motor skills were randomly divided into a model group and a control group, with 14 mice in each group.A PD model was established by injecting preformed fibrils of α-syn into the striatum of the brain, and behavioral changes were monitored after 4 weeks.The expression levels of α-syn, the dopamine receptor(DR), tyrosine hydroxylase(TH), inflammatory factors, β-arrestin 2 and the nuclear transcription factor-κB(NF-κB)signaling pathway-related proteins were determined by Western blotting.The interaction between α-syn and β-arrestin 2 was detected by fluorescence resonance energy transfer(FRET), and the regulation of α-syn on β-arrestin 2 transcriptional activation was detected by the dual luciferase report assay.Results:After 4 weeks of modeling, compared with the control group, the average movement speed of mice in the model group was significantly reduced( t=9.415, P<0.001), the movement track was sparse and concentrated around the open field, and the time needed to climb the pole was significantly prolonged( t=16.412, P<0.001). Compared with the control group, the relative expression of α-synin in astrocytes in the model group increased significantly, the relative expressions of D1DR and TH decreased significantly[(1.14±0.18) vs.(0.53±0.16), (0.67±0.13) vs.(1.15±0.11), (0.46±0.05) vs.(0.81±0.06)]( t=9.810, 10.917 and 17.356, all P<0.001), the relative expression of tumor necrosis factor-α, interleukin-1β, interleukin-6 and NF-κB signaling pathway-related proteins increased significantly( t=3.583, 4.284, 5.396, 11.747, 16.375 and 18.294, all P<0.001), and the relative expression of β-arrestin 2 protein[(0.42±0.11) vs.(1.33±0.14)]in astrocytes decreased significantly( t=19.795, P<0.001). The FRET results suggested a possible direct interaction between α-syn and β-arrestin 2.The results of the dual luciferase report assay showed that the transcription activity of β-arrestin 2 was significantly increased after α-syn gene knockout. Conclusions:The α-syn may induce inflammation in astrocytes by activating the NF-κB signaling pathway and participate in the pathogenesis of PD by reducing dopamine biosynthesis and inhibiting its physiological function through negative regulation of β-arrestin 2.

Impact of oxidative stress on renal dopamine D1 receptor dysfunction in offspring of diabetic rat dams / 中华心血管病杂志

Objective@#To explore the effects of oxidative stress on renal dopamine D1 receptor dysfunction in offspring of diabetic rat dams.@*Methods@#The pregnant Sprague Dawley (SD) rats (n=10) were randomly divided into the diabetic group (a single intraperitoneal injection of 35 mg/kg streptozotocin on day 0 of gestation) and control group (injected with the equal volume of 0.9% saline on day 0 of gestation) according to the random number table (n=5 each group). The offspring rats were divided into 4 groups including offspring of control dams treated with vehicle, offspring of control dams treated with antioxidant, offspring of diabetic dams treated with vehicle and offspring of diabetic dams treated with antioxidant (n=10 each group). After birth, the offspring rats were treated with normal drinking water or antioxidant (tempol, 1.0 mmol/L) from the age of 4 weeks until the end of the study (20 weeks). The blood pressure was monitored continuously by non-invasive tail-cuff method. The renal oxidative markers including superoxide dismutase (SOD) and malondialdehyde (MDA) activity and D1 receptor agonist (fenoldopam)-mediated urinary and sodium excretion were detected. Furthermore, the protein expression of renal G protein-coupled receptor kinase 2 (GRK2), GRK4, dopamine D1 receptor and the phosphorylation level of D1 receptor were detected.@*Results@#The mean arterial pressure of offspring from the diabetic dams treated with vehicle was significantly higher than that of offspring from control dams treated with vehicle (P=0.013), while the mean arterial pressure of offspring from diabetic dams treated with antioxidant was significantly lower than that of offspring from the diabetic dams treated with vehicle (P=0.038). The fenoldopam-mediated urinary flow and urinary sodium excretion rate were significantly lower in offspring of diabetic dams treated with vehicle than those in offspring of control dams treated with vehicle (P<0.01), which were significantly higher in offspring of diabetic dams treated with antioxidant as compared to offspring of diabetic dams treated with vehicle (both P<0.01). There was no significant difference in fenoldopam-mediated urinary flow and urinary sodium excretion rate in offspring of control dams treated with antioxidant or vehicle (urinary flow: P=0.772; urinary sodium excretion rate: P=0.716). Compared with offspring of control dams treated with vehicle, the renal MDA activity was significantly increased, while the SOD activity was significantly decreased in offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.013). The renal MDA activity was significantly decreased, while the SOD activity was significantly increased in offspring of diabetic dams treated with antioxidant in comparison with offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.035).The renal GRK2 and GRK4 protein expression in offspring of diabetic dams treated with vehicle were significantly higher than those in offspring of control dams treated with vehicle (P<0.01), while the expression levels of renal GRK2 and GRK4 in offspring of diabetic dams treated with antioxidant were significantly downregulated compared with offspring of diabetic dams treated with vehicle (P<0.01). There was no significant difference in the protein expression of dopamine D1 receptor among 4 groups (P=0.735). The level of dopamine D1 receptor phosphorylation in offspring of diabetic dams treated with vehicle was significantly higher than that in offspring of control dams treated with vehicle (P<0.01), while the dopamine D1 receptor phosphorylation level was significantly lower in offspring of diabetic dams treated with antioxidant compared to that in offspring of diabetic dams treated with vehicle (P<0.01).@*Conclusion@#Oxidative stress is involved in the dopamine D1 receptors dysfunction in the offspring of diabetic dams.

Frequência de polimorfismos genéticos rs1800497, rs1799732, rs6280 e a ocorrência da esquizofrenia refratária / Frecuencia de polimorfismos genéticos rs1800497, rs1799732, rs6280 y la ocurrencia de la esquizofrenia refractory / Frequency of genetic polymorphisms rs1800497, rs1799732, rs6280 and the occurrence of schizophrenia refractory

Introdução: a esquizofrenia é considerada um dos mais severos e complexos transtornos mentais que acomete tanto a qualidade de vida do indivíduo que convive com a doença quanto a de sua família. Caracteriza-se principalmente por sintomas denominados positivos (alteração no processo do pensamento, percepções e afeto) e negativos (embotamento afetivo-volitivo,perdas cognitivas e sintomas depressivos). Os fatores de risco para este transtorno são epifenômenos de processos fisiopatológicos que resultam de uma interação gene-ambiente ainda pouco compreendida. A hipótese da dopamina é o principal conceito que fundamenta a atividade antipsicótica, conforme esta, os sintomas positivos estariam relacionados a níveis elevados de dopamina na via mesolímbica, enquanto os sintomas negativos e cognitivos,possivelmente estão associados a níveis diminuídos desse neurotransmissor na viamesocortical. Os antipsicóticos cessam os sintomas da esquizofrenia, no entanto, 40% dospacientes permanecem resistentes (refratários) ao tratamento. Os pacientes com esquizofreniarefratária ao tratamento apresentam menor capacidade de síntese de dopamina do que aquelescom boa resposta aos antipsicóticos de primeira geração, sendo que uma adequada resposta aotratamento medicamentoso coincidi com uma maior densidade de sinapses dopaminérgicas,isto subsidia uma base biológica para a refratariedade. O polimorfismo de nucleotídeo simplesé uma variação da sequência de DNA devido a uma única diferença de nucleotídeos entre osalelos. Alguns deles podem ter efeitos funcionais e podem alterar a regulação positiva da expressão do receptor induzida por dopamina. Três principais destes polimorfismos foramabordados neste estudo: rs1800497, rs1799732 e rs6280. Objetivo: investigar a frequência dospolimorfismos rs1800497, rs1799732 e rs6280 e a ocorrência da esquizofrenia refratária

Introduction: Schizophrenia is considered one of the most severe and complex mentaldisorders that affect both the quality of life of the individual living with the disease and that ofhis family. It is characterized mainly by symptoms denominated positive (alteration in thethought process, perceptions and affection) and negative (affective-volitional blunting,cognitive losses and depressive symptoms). The risk factors for this disorder areepiphenomena of pathophysiological processes that result from a gene-environmentinteraction still poorly understood. The hypothesis of dopamine is the main conceptunderlying antipsychotic activity, as this, positive symptoms would be related to elevateddopamine levels in the mesolimbic pathway, while negative and cognitive symptoms arepossibly associated with decreased levels of this neurotransmitter in the mesocorticalpathway. Antipsychotics cease the symptoms of schizophrenia, however, 40% of patientsremain resistant (refractory) to treatment. Patients with treatment-refractory schizophreniahave a lower capacity for dopamine synthesis than those with a good response to first-generation antipsychotics, and an adequate response to drug treatment coincided with a higherdensity of dopaminergic synapses, this subsidizes a biological basis for refractoriness. Singlenucleotide polymorphism is a variation of the DNA sequence due to a single nucleotidedifference between the alleles. Some of them may have functional effects and may alter thepositive regulation of dopamine-induced receptor expression. Three major of thesepolymorphisms were addressed in this study: rs1800497, rs1799732 and rs6280. Objective:to investigate the frequency of polymorphisms rs1800497, rs1799732 and rs6280 and theoccurrence of refractory schizophrenia

Non-displaceable binding potential changes of striatal dopamine D2 receptors in patients with first-episode major depressive disorder and the correlation with clinical features / 中华核医学与分子影像杂志

Objective To observe non-displaceable binding potential (BPND) changes of striatal dopamine D2 receptors(SDDR) in patients with first-episode major depressive disorder (MDD) using 11C-Raclopride PET/CT,and to analyze the relationship between BPND and Hamilton rating scale for depression (HAM-D).Methods From December 2014 to December 2015,patients with first-episode MDD and age/gender-matched healthy controls underwent brain MRI and 11C-Raclopride PET/CT in this prospective study.BPND of bilateral SDDR was calculated by molecular imaging and kinetic analysis toolbox (MIAKAT).BPND changes of bilateral SDDR and their relationship with HAM-D score were analyzed.Paired t test,two-sample t test and Pearson correlation analysis were used.Results A total of 20 MDD patients (8 males,12 females,average age: (32.80±9.76) years) and 20 healthy controls (9 males,11 females,average age:(29.25±6.93) years) were enrolled in this study.The 11C-Raclopride uptake in brain tissue of the MDD group and control group were mainly distributed in bilateral striatum,and very few 11C-Raclopride was distributed in bilateral cerebral cortex and cerebellum.In MDD group,the BPND level of bilateral SDDR had no statistical differences(t values: 0.69,0.35,both P>0.05),and similar results were found in the control group(t values: 0.28,0.24,both P>0.05).Compared with the control group,however,the MDD group had lower BPND level of bilateral SDDR(t values: 3.13-4.41,all P<0.05).The BPND of bilateral caudate nucleus and/or putamen D2 receptors was correlated with HAM-D total score,anxiety/somatization factor score,cognitive impairment factor score,retardation factor score and sleep disturbance factor score(r values: from-0.688 to-0.453,all P<0.05).Conclusions The binding potential of SDDR in patients with first-episode MDD is declined,and the BPND level of SDDR is correlated with symptoms of depression.The abnormality of SDDR may be an important molecular mechanism of the abnormality of midbrain-striatal dopamine reward circuits in MDD patients.

Multiple modalities PET/CT neuroimaging for the diagnosis of Parkinson's disease and multiple system atrophy: statistical parametric mapping analysis / 中华神经科杂志

Objective To investigate the topographic distributions of dopamine transporter (DAT),dopamine D2 receptor and glucose in Parkinson's disease (PD) and multiple system atrophy (MSA) using positron emission tomography/computed tomography (PET/CT) scanning and statistical parametric mapping (SPM) analysis.Methods Seventy subjects (39 PD patients,15 MSA patients and 16 normal controls) who came from People's Liberation Army General Hospital from September 2013 to November 2015 underwent DAT,D2 receptor and glucose brain PET/CT scans using 11 C-methyl-N-2-β-carbomethoxy-3-β-(4-fluorophenyl) tropane (11C-β-CFT),11C-raclopride and 18F-fluorodeoxyglucose (18 F-FDG) as radiotracers,respectively.The uptake patterns were analyzed using SPM software.Results Striatal DAT binding decreased in the putamen in PD patients compared with controls (Z =5.21-5.77,P =0.002-0.016).D2 receptor showed no significant differences.However,glucose uptake decreased in cingulate gyrus(Z =4.51-4.67,P =0.010-0.017).For MSA patients,both DAT and D2 receptor binding decreased in the putamen(Z =2.13-3.42,P =0.000-0.016).Glucose uptake decreased in the bilateral putamen,cerebellum and part of frontal temporal lobes (Z =1.86-3.75,P =0.000-0.032).Conclusion Multiple modalities PET/CT scans using the ligands 11 C-β-CFT,11C-raclopride,and 18F-FDG are valuable in diagnosis of MSA and differential diagnosis of MSA from PD.

Reduction of Severity of Recurrent Psychotic Episode by Sustained Treatment with Aripiprazole in a Schizophrenic Patient with Dopamine Supersensitivity: A Case Report

Dopamine supersensitivity psychosis (DSP) is a type of acute exacerbation of recurrent psychosis caused by long-term treatment with antipsychotics in schizophrenic patients. Although DSP is exceedingly troublesome for clinicians, effective treatment has not yet been established. Based on clinical research and our animal study, we hypothesize that aripiprazole, an atypical anti-psychotic, may reduce the exacerbation of recurrent psychotic episodes. We report the case of a 46-year-old female who suffered from schizophrenia with DSP. In this case, sustained treatment with a high dose of aripiprazole gradually reduced the severity of her recurrent psychotic episodes. In conclusion, sustained treatment with aripiprazole may reduce the exacerbation of recurrent psychotic episodes in schizophrenic patients with DSP, and may be an effective treatment of DSP.

Constructing the dual luciferase reporter vector containing human DRD1 promoter region / 中国组织工程研究

BACKGROUND:The polymorphisms of dopamine receptor in promoter region wil affect the expression of the receptor, thereby affecting the dopaminergic neurotransmitter, final y lead to related diseases. OBJECTIVE:To construct the dual luciferase reporter vector containing human DRD1 promoter region and determine its activity, which could provide the basic tool for studying the transcriptional regulation of DRD1 gene. METHODS:DRD1 promoter sequence was amplified by PCR using the human blood genomic DNA and cloned into pGM-T vector. After sequencing, the correctly constructed vectors were ligated to the firefly luciferase reporter plasmid pGL3-Basic. The cloned pGL3-Basic vectors were transfected into HEK293 using cationic liposome method. In the meanwhile, PGL3-Basic vector with no promoter was co-transfected with pGL3-TK plasmid as negative control group. The relative fluorescence intensity was measured by chemiluminescence. RESULTS AND CONCLUSION:(1) Recombinant luciferase reporter gene vectors were confirmed by restriction analysis and sequencing. (2) Compared with the negative control group, the HEK293 cel s transfected by recombinant vectors presented transcriptional activity. (3) In conclusion, luciferase reporter gene vectors containing DRD1 promoter region are successful y constructed and can provide the basic tool for further study on the transcriptional regulation of DRD1.

Nicergoline improves the depressive behavior of vascular depression in rats by regulating monoamine neurotransmitter receptors expression in hippocampal CA1 region and serum apolipoprotein E4 level / 国际脑血管病杂志

Objective To investigate the effects of nicergoline on expressions of 5-hydroxytryptamine 1A receptor (5-HT1AR), D2 dopamine receptor (D2DR),α2A adrenaline receptor (α2AAR) in the hippocampal CA1 region and the serum level of apolipoprotein E4 (ApoE4) in a rat model of vascular depression (VD) . Methods Forty-eight male Sprague-Daw ley rats w ere randomly al ocated into a normal control group, a model group, fluoxetine group, a low-dose nicergoline group, a medium-dose nicergoline group, and a nicergoline high-dose group ( n=8 in each group). A rat model of VD w as induced by the ligation of bilateral common carotid arteries combined w ith chronic unpredictable mild stress (CUMS) plus single housing. The rats did not conduct CUMS or single housing in the normal control group, and the rats in the model group conducted CUMS and single housing. The rats in the fluoxetine group w ere given fluoxetine 1.3 mg/(kg· d) for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The rats in the low -, medium-and high-dose nicergoline groups w ere given nicergoline 0.9, 1.9 and 3.8 mg/(kg· d), respectively for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The normal control group and the model group w ere given equal volume of distil ed w ater for gastric lavage, once a day for 3 w eeks. Depression-like behavior w as evaluated using sucrose solution consumption and open-field test. Immunohistochemical staining and Western blot were used to detect the expressions of 5-HT1AR, D2DR, andα2AAR in the hippocampal CA1 region. Enzyme linked immunosorbent assay w as used to detect serum ApoE4 level. Results Before CUMS, the scores of horizontal and vertical movement and sucrose solution consumption in the model group, the fluoxetine group and each nicergoline group w ere decreased significantly compared w ith the normal control group (al P<0.01);w hile at 21 days after CUMS, those in the fluoxetine group and the nicergoline medium-and high-dose groups w ere significantly higher than those in the model group (al P<0.05). There w ere no significant differences betw een the fluoxetine group and each nicergoline group. The expression levels of 5-HT1A R, D2DR, α2A AR, and the serum ApoE4 in the model group, the fluoxetine group, and each nicergoline group w ere significantly higher than those in the normal control group. Those of the fluoxetine group and the nicergoline medium -and high-dose groups were significantly lower than the model group (al P<0.01), while there were no significant differences betw een the fluoxetine group and each nicergoline group. Conclusions Nicergoline can improve the depression-like behavior in VD rats. Its mechanism may be associated w ith the dow nregulation of 5-HT1AR, D2DR, α2AAR expressions and serum ApoE4 level.

Role of spinal dopamine D2 receptors in a rat model of neuropathic pain / 中华麻醉学杂志

Objective To evaluate the role of spinal dopamine D2 receptors in a rat model of neuropathic pain.Methods Thirty healthy male Sprague-Dawley rats,aged 6-8 weeks,weighing 180-200 g,wcre randomly divided into 5 groups (n =6 each) using a random number table:control group (group C),sham operation group (group S),neuropathic pain group (group NP),normal saline group (group N) and dopamine D2 receptor agonist quinpirole group (group Q).Neuropathic pain was produced by chronic constriction injury of the sciatic nerve (CCI) in rats anesthetized with intraperitoneal 2％ pentobarbital sodium 40 mg/kg.At 7 days after CCI,normal saline 10 μl was injected intrathecally over 30 s in group N,and quinpirole 10 μg (in 10 μl of normal saline) was injected intrathecally over 30 s in group Q.At 1 day before CCI,3 and 7 days aher CCI,and 30 min and 1,2,4,8 and 16 h after administration,mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured.Results There was no significant difference in MWT and TWL at each time point between group C and group S.MWT was significantly lower,and TWL was shorter at T1-8 in NP,N and Q groups than in C and S groups.Compared with group N,no significant change was found in MWT and TWL at each time point in N group,and MWT was significantly increased,and TWL was prolonged at T4-6 in group Q.Conclusion Inhibited function of spinal dopamine D2 receptors is involved in the maintenance of neuropathic pain in rats.

Study on relationship between single nucleotide polymorphisms polymorphisms of DDC and DRD1 and clinical phenotype feature in autistic children / 中国医师杂志

Objective To investigate the association between single nucleotide polymorphisms (SNPs) of DOPA decarboxylase (DDC) and dopamine receptor-1 (DRD1) and clinical phenotype feature in autistic children.Methods TaqMan probes real-time polymerase chain reaction (PCR) was used to determine genotype and allele of SNPs of DDC gene (rs6592961) and DRD1 (rs251937) gene in 97 autism children.The Children Autism Rating Scale (CARS) was used to evaluate clinical phenotype feature.Results There was no significant difference in the distribution of the allelic frequency and genotype between mild-medium group and severe group of CARS scores (P ＞ 0.05).For DDC gene (rs6592961),significant difference was found in subscale between genotypes G/G and A/A (P =0.043).For DRD1 gene (rs251937),significant difference was found in subscale between genotypes T/T and C/C (P =0.029).Conclusions In DDC gene (rs6592961),the children with G/G genotype were more obvious than the children with A/A genotype.In DRD1 gene (rs251937),the children with T/T genotype were more obvious than the children with C/C genotype.

Expression of dopamine D1 receptors in hippocampal dentate gyrus in rats with vascular dementia / 吉林大学学报(医学版)

Objective To observe the extracellular content of dopamine (DA)and expression of D1 receptors in hippocampal dentage gyrus (DG)in the model rats with vascular dementia (VD),and to investigate the relationship between them.Methods 12 male SD rats were randomly divided VD group and sham-operation group,and the VD model was prepared by permanent bilateral carotid occlusion.The extracellular content of DA in the DG was determined by in vivo microdialysis and HPLC,and the expression of D1 receptors was measured by immunehisto-chemistry.Results The DA content in the DG of the rats in VD group was lower than that in sham-operation group (P 0.05).Conclusion The DA content in the hippocampal DG is decreased in the VD rats,and its function may be compensated by the up-regulation of D1 receptors in the DG hilus.

Brain imaging of 18 F-Fallypride in healthy volunteers / 中华核医学与分子影像杂志

Objective To evaluate dopamine D2/D3 receptors status in striatal and extra?striatal re?gions with 18 F?Fallypride PET/CT. Methods A total of 11 healthy volunteers ( 4 males, 7 females, age (43.5±13.7) years) underwent PET/CT at 1 h after 18F?Fallypride injection. Imaging data was analyzed u?sing visual and ROI methods. The SUV ratios of different brain regions to cerebellar lobe were calculated. In?formed consent was obtained from all volunteers. The study was approved by the Ethics Committee of the PLA General Hospital. Results 18 F?Fallypride was widely distributed in striatal and extra?striatal brain re?gions. Distribution of 18 F?Fallypride was consistent in all healthy subjects and the rank order of receptor con?centration(brain region SUV/cerebellum SUV) was putamen(15.72±3.69)>pituitary(10.24±6.55)>cau?date(8.38±1.26)>amygdala(6.92±1.32)>thalamus(4.87±1.50)>colliculi(3.91±1.08)>substantia nigra (3.20±0.95)>cortex(temporal cortex: 2.11±1.34, parietal cortex: 1.51±0.57, occipital cortex: 1.31± 0?11, frontal cortex:1?30±0.25). Conclusion 18F?Fallypride PET/CT is suitable to study D2/D3 recep?tors status in striatal and extra?striatal brain regions.

Relationship between Genetic Polymorphism of Dopamine Receptor and Schizophrenia and Its Forensic Significance / 法医学杂志

Schizophrenia is a common but complex mental disorder affected by multiple factors. Forensic psychiatric assessment of schizophrenia involves evaluations on many aspects, but there is no effective biological identification index for schizophrenia. Researches indicate that dysfunction of dopaminergic neurotransmission plays an important role in the pathogenesis of schizophrenia. Our study reviews the classification, genetic structure of dopamine receptors and the recent pertinent studies between the dopamine receptors and schizophrenia and its forensic significance.

Role of dopamine receptor in intestinal mucosal barrier change after brain injury in rats / 中华创伤杂志

Objective To investigate the effect of dopamine receptor in intestinal mucosal barrier function after brain injury in rats.Methods Twenty-four rats were allocated to control group,brain injury group,dopamine receptor group,and dopamine antagonist group according to the random number table,with 6 rats per group.Feeney' s weight-drop model was introduced to generate rat models of brain injury.Intestinal mucosal specimens were harvested at postoperative 7 days to evaluate intestinal mucosal morphology by HE staining,expressions of dopamine receptor D1 (DRD1) and dopamine receptor D2 (DRD2) by immunohistochemistry,and mRNA and protein expressions of DRD1 and DRD2 by real-time PCR and Western blot.Meantime,urinary samples were collected to measure lactulose to mannitol ratio (L/M) by high performance liquid chromatography (HPLC).Results Intestinal villus integrity was disrupted in brain injury group and dopamine receptor group when compared to control group,but it remained relatively intact in dopamine antagonist group.Ratio of L/M in brain injury group and dopamine receptor group was similar (0.192 ± 0.080 vs 0.183 ± 0.090,P ＞ 0.05),far higher than 0.037 ± 0.008 in control group (P ＜0.01),but it was reversed in dopamine antagonist group (0.071 ± 0.008,P ＜ 0.01).Real-time PCR showed DRD1 and DRD2 mRNAs expressed in brain injury group and dopamine receptor group were similar (0.764 ± 0.074 vs 0.718 ± 0.065,0.439 ± 0.051 vs 0.408 ± 0.090,P ＞ 0.05),far higher than 0.189 ± 0.008 and 0.076 ± 0.011 in control group (P ＜ 0.01),but both lowered in dopamine antagonist group (0.386 ± 0.071,0.270 ± 0.092,P ＜ 0.01).estern blot analysis showed DRD1 and DRD2 proteins in brain injury group and dopamine receptor group were similar,but both were far higher when compared to control group (P ＜ 0.01).Conclusion Impaired intestinal mucosal barrier may be relate to the up-regulated dopamine receptor in intestinal mucosa after brain injury in rats.

Riesgo de déficit atencional/hiperactividad en escolares Aymara, Rapa-Nui y de Santiago de Chile: Posible contribución de polimorfismos genéticos del sistema dopaminérgico / Risk of attention deficit/hyperactivity disorder in Aymara and Rapa-Nui school children: Association with dopaminergic system polymorphisms

Background: Attention deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness or inattentiveness. Aim: To search for differences in risk for ADHD and its components among Chilean native and mixed populations and to look forpossible associations with dopamine receptor D4 (DRD4) and dopamine transporter 1 (DAT1) polymorphisms. Material and Methods: School teachers were requested to complete the Conners test, which uses DSM-IV criteria, to screen for ADHD risk among Aymara and Rapa-Nui students. Results: Rapa-Nui children from Easter Island had the highest risk of hyperactivity/impulsiveness. Aymara children from the Arica-Parinacota Region had lower scores. Although inattentiveness scores had lower differences between groups, overall ADHD score differences among studied populations were highly significant. DRD4 and DAT1 alleles had a heterogeneous distribution. Easter islanders had more divergent frequencies, mostprobably as a result of separate migration routes utilized at different timeperiods during the colonization of America and Polynesia. Conclusions: The comparison of ADHD risk parameters between Rapa-Nui and Aymara children showed marked differences. Allele distri-bution of dopamine polymorphisms in Easter Island was also significantly different from northern Chile, due probably to different colonization histories. These findings suggest that higher ADHD risk scores in Easter Island children may be linked to the presence of different DRD4 alleles.

Associations between DRDs and schizophrenia in a Korean population: multi-stage association analyses

The dysregulation of the dopaminergic system has been implicated in the pathophysiology of major psychosis, including schizophrenia, with dopamine receptor genes (DRDs) presently targeted as the most promising candidate genes. We investigated DRD1-5 for association with schizophrenia using a multi-stage approach in a Korean sample. One hundred forty-two SNPs in DRD1-5 were selected from the dbSNP, and the associations of each SNP were then screened and typed by MALDI-TOF mass spectrometry using pooled DNA samples from 150 patients with major psychosis and 150 controls. Each of the suggested SNPs was then genotyped and tested for an association within the individual samples comprising each pool. Finally, the positively associated SNPs were genotyped in an extended sample of 270 patients with schizophrenia and 350 controls. Among the 142 SNPs, 88 (62%) SNPs in our Korean population were polymorphic. At the pooling stage, 10 SNPs (DRD1: 2, DRD2: 3, and DRD4: 5) were identified (P < 0.05). SNPs rs1799914 of DRD1 (P = 0.046) and rs752306 of DRD4 (P = 0.017) had significantly different allele frequencies in the individually genotyped samples comprising the pool. In the final stage, with the extended sample, the suggestive association of DRD4 with rs752306 was lost, but the association of DRD1 with rs1799914 gained greater significance (P = 0.017). In these large-scale multi-stage analyses, we were able to find a possible association between DRD1 and schizophrenia. These findings suggested the potential contribution of a multi-step strategy for finding genes related to schizophrenia.

Biological evaluation of ~(18)F-FDTP as a potential dopamine D_4 receptor PET imaging agent / 中华核医学杂志

Objective To evaluate the feasibility of 3-(4-~(18)F-fluorobenzyl)-8,9-dimethoxy-1,2,3,4-tetrahydrochromeno [3,4-c]pyridin-5-one ( is F-FDTP) as a potential dopamine D4 receptor PET imaging agent.Methods ~(18)F-FDTP solution in ethanol-physiological saline was incubated with calf serum to test its in vitro stability through the determination of radiochemical purity.Normal rats were injected intravenously with ~(18)F-FDTP and then sacrificed at 2,5,10,15,30,60 and 120 min after anesthesia.Blood,organs and brain tissue samples were collected.All samples were weighed and measured for radioactivity.The uptake of samples was expressed as percentage activity of injection dose per gram of tissue ( % ID/g).Results The stability of ~(18)F-FDTP was satisfactory and its radiochemical purity was above 95% after incubation 120 min at 37℃ in calf serum.The biodistribution showed that ~(18)F-FDTP could penetrate through the blood-brain barrier and selectively accumulate in striatum,hypothalamus,frontal certex,hippocampus,cerebellum,where the D_4 receptor was reportedly located.The radioactivities in hippocampus,hypothalamus,striatum,frontal cortex,cerebellum,pons were (0.42±0.03),(0.46±0.05),(0.54±0.04),(0.39±0.04),(0.45±0.06),(0.35±0.04) %ID/g,respectively,2 min post injection.And there was difference between the normal biodistribution results and the blocking experimental results:(0.36 ±0.05),( 0.33±0.05 ),(0.55±0.05 ),(0.30±0.07 ),(0.34±0.07 ) and (0.32±0.04) % ID/g in hippocampus,hypothalamus,striatum,frontal cortex,cerebellum and pons,respectively.Conclusions ~(18)F-FDTP can penetrate through the blood-brain barrier and selectively accumulate in striatum,hypothalamus,frontal cortex,hippocampus,cerebellum,where the D_4 receptor was known to concentrate.These preliminary results suggest that ~(18)F-FDTP is a potential dopamine D_4 receptor imaging agent and further studies are needed.

Effects of terguride on protein and mRNA expressions of dopamine D2 receptor and dynorphin in different brain regions of rats after heroin self administration / 中国药理学与毒理学杂志

OBJECTIVE To study mechanisms of terguride on the treatment of herion dependence. METHODS Adult male SD rats were randomly assigned into 5 groups: normal control group, saline treatment during heroin use period group, terguride treatment during heroin use period group, saline treatment during heroin reinstatement period group, terguride treatment during heroin reinstatement period group, the last 4 groups established heroin intravenous self administration and cue induced reinstatement models, and after interfernce and perfusion to get the following five brain regions [including ventral tegmental area (VTA)]sections. The expression of dopamine D2 receptor protein and mRNA, prodynorphin protein and preprodynorphin mRNA was detected by immunohistochemistry and hybridization in situ. RESULTS The expression of dopamine D2 receptor was downregulated during heroin use period and upregulated during heroin reinstatement period in nucleus accumbens shell (AcbSH) region, the expression of dopamine D2 receptor mRNA was parallelled with the protein expression approximately, terguride could downregulate the high expression of receptor protein during reinstatement. The expression of dopamine D2 receptor protein and mRNA was upregulated during heroin reinstatement period in central nucleus amygdalae (CeA) region, and terguride could downregulate this high expression. The expression of dopamine D2 receptor protein and mRNA was upregulated during heroin use period and downregulated during heroin reinstatement period in CA1 region of hippocampus and prefrontal cortex (PFC), terguride could downregulate the high expression of mRNA during heroin reinstatement period. The expression of dynorphin protein and mRNA was upregulated during heroin reinstatement period, terguride could downregulate this high expression. The expression of dynorphin protein was upregulated during heroin reinstatement period, and terguride could downregulate this high expression. CONCLUSION The activity of mesolimbic dopamine is boosted up during heroin use period and depressed during reinstatement period, terguride can regulate this dysregulation. The activity of dynorphin is boosted up during cue induced reinstatement, and terguride has the downregulation effect. So the preclinic study demonstrated that terguride has the potential benefit in heroin dependence.

Association Study between Tic Disorder and Dopamine D2 Receptor Gene Polymorphism in Korean Population

OBJECTIVES: The purpose of the present study was to investigate whether the Taq I A polymorphism of dopamine receptor D2 gene(DRD2) is associated with Tourette syndrome(TS) and chronic motor tic disorder(CMT) in Korean population. METHODS: DRD2 Taq I A RFLP genotyping was carried out with DNA extracted from blood samples of 75 patients with tic disorders(47 with TS and 28 with CMT) and 90 healthy subjects. Genotype and allelic frequencies for the DRD2 gene polymorphisms of the tic disorder group as a whole were compared to those of the control group. Separating the TS group, thereafter, the frequency of genotypes and alleles were compared to those of the controls. RESULTS: The results demonstrated that genotype and allele distributions for the DRD2 gene polymorphism in the tic disorder as a whole, TS, and control groups were not significantly different. CONCLUSION: No association was found for DRD2 gene, TS and CMT. The data suggest that DRD2 gene may not be a useful marker for the prediction of the susceptibility of tic disorder.

Association analysis of dopamine D4 receptor gene polymorphism and attention deficit hyperactivity disorder with/without disruptive behavior disorder / 北京大学学报(医学版)

Objective:To examine the role of dopamine D4 receptor gene(DRD4) in attention deficit hyperactivity disorder(ADHD) with/without disruptive behavior disorder(DBD) by focusing on a-521C/T SNP within the promoter region of this gene.Methods:A total of 401 DSM-Ⅳ ADHD children(including 284 trios) of Chinese Han descent were genotyped.Chi-square test and the transmission disequilibrium test(TDT) were used to test for associations in ADHD with and without DBD respectively.Results:In the comparison of ADHD with(n= 143) and without(n= 258) DBD,the-521T allele(?2 = 6.778,P= 0.009,OR= 1.485) and the TT genotype(?2 = 6.292,P= 0.012,OR= 1.729) showed higher frequency in children with ADHD and DBD simultaneously.For family based analysis,T allele of the-521C/T polymorphism was preferentially transmitted to ADHD children with comorbid DBD(n= 100,?2 = 3.868,P= 0.049),whereas no significant distortion was found in the transmission of the tested variant for ADHD without DBD(n= 184,?2 = 0.223,P= 0.637).Conclusion:Our findings suggest that the-521C/T SNP of DRD4 may contribute to the predisposition to ADHD with comorbid DBD.This study supports for the hypothesis that ADHD with comorbid DBD may be influenced by greater genetic effect compared to ADHD alone.