The Experts below are selected from a list of 474 Experts worldwide ranked by ideXlab platform

Murali Naidu - One of the best experts on this subject based on the ideXlab platform.

  • methanolic extract of mitragyna speciosa korth leaf inhibits ethanol seeking behaviour in mice involvement of Antidopaminergic mechanism
    Metabolic Brain Disease, 2019
    Co-Authors: Kamini Vijeepallam, Vijayapandi Pandy, Dharmani Devi Murugan, Murali Naidu
    Abstract:

    In the current study, the effect of methanolic extract of Mitragyna speciosa leaf (MMS) against the rewarding and reinforcing properties of ethanol using a mouse model of conditioned place preference (CPP) and runway model of drug self-administration was studied. Subsequently, the effect of MMS on dopamine level in the nucleus accumbens (NAc) of the mouse brain was further investigated. From the data obtained, MMS (50 and 75 mg/kg, p.o.) significantly reversed the ethanol-place preference in mice, which is similar to the effect observed in the reference drugs acamprosate (300 mg/kg, p.o.) and clozapine (1 mg/kg, p.o.) treatment groups in CPP test. Likewise, the escalating doses of ethanol-conditioned mice reduced the runtime to reach goal box, infers the positive reinforcing effects of alcohol. Interestingly, MMS (50, 75 and 100 mg/kg, p.o.) significantly prolonged the runtime in ethanol-conditioned mice. Besides, MMS (50 and 75 mg/kg, p.o.) and reference drugs; acamprosate (300 mg/kg, p.o.) and clozapine (1 mg/kg, p.o.) treated mice significantly decreased the alcohol-induced elevated dopamine level in the NAc region of the brain. Overall, this study provides first evidence that MMS inhibits ethanol seeking behaviour in mice. Based on these findings, we suggest that Mitragyna speciosa may well be utilized for novel drug development to combat alcohol dependence.

Sunao Kaneko - One of the best experts on this subject based on the ideXlab platform.

  • Combination of dopamine D2 receptor gene polymorphisms as a possible predictor of treatment-resistance to dopamine antagonists in schizophrenic patients.
    Progress in neuro-psychopharmacology & biological psychiatry, 2003
    Co-Authors: Tsuyoshi Kondo, Kazuo Mihara, Akihito Suzuki, Norio Yasui-furukori, Sunao Kaneko
    Abstract:

    Both the A1 allele carriers of TaqI A and Del allele noncarriers of −141C Ins/Del for dopamine D2 receptor (DRD2) gene polymorphisms have been reported to have a lowered DRD2 density. The present study aimed to examine whether the combinations of these two DRD2 gene polymorphisms predict treatment response to Antidopaminergic agents in schizophrenic patients. Subjects consisted of 49 acutely exacerbated schizophrenic inpatients treated with bromperidol (30 cases, mean dose±S.D.: 11.4±4.8 mg/day) or nemonapride (19 cases, 18 mg/day). Clinical symptoms were evaluated using Brief Psychiatric Rating Scale (BPRS) before and 3 weeks after the treatment. DRD2 genotypes were determined using a polymerase chain reaction method. The A1 noncarriers with a Del allele showed poorer percentage improvement in anxiety–depression symptom after 3-week treatment (n=9, 7.3±42.9%) than A1 carriers without Del alleles (n=25, 62.4±38.0%) or A1 noncarriers without Del alleles (n=10, 65.4±29.2%). However, these preliminary results should be replicated in further research with a larger number of the subjects in each haplotype subgroup.

  • prolactin response to zotepine in schizophrenic patients
    Human Psychopharmacology-clinical and Experimental, 1993
    Co-Authors: K Otani, Hiroshi Sasa, Hisashi Higuchi, Tsuyoshi Kondo, Sunao Kaneko, Masayuki Ishida, Yutaka Fukushima
    Abstract:

    The prolactin response to an antipsychotic drug zotepine, which has both Antidopaminergic and antiserotonergic effects, was studied in 24 inpatients suffering from schizophrenia. The daily dose was 100 mg in the first week, and 200 mg for the next three weeks. The mean serum concentrations of prolactin at the daily dose of 200 mg, but not 100 mg, were significantly higher than that before treatment. The δ prolactin (the change from the pretreatment concentration) was significantly correlated with zotepine concentrations at each week. At low zotepine concentrations, patients with high pre-treatment prolactin concentrations showed negative δ prolactin. The present study thus suggests that at high concentrations zotepine shows predominantly Antidopaminergic effects, while at low concentrations its antiserotonergic effects are predominant and/or it acts as a dopamine agonist.

Roger A Barker - One of the best experts on this subject based on the ideXlab platform.

  • Antidopaminergic treatment is associated with reduced chorea and irritability but impaired cognition in huntington s disease enroll hd
    Journal of Neurology Neurosurgery and Psychiatry, 2020
    Co-Authors: Kate Harris, Weili Kuan, Sarah L Mason, Roger A Barker
    Abstract:

    Objectives Alterations in dopamine neurotransmission underlie some of the clinical features of Huntington’s disease (HD) and as such are a target for therapeutic intervention, especially for the treatment of chorea and some behavioural problems. However, justification for such an intervention is mainly based on case reports and small open label studies and the effects these drugs have on cognition in HD remain unclear. Methods In this study, we used the Enroll-HD observational database to assess the effects of Antidopaminergic medication on motor, psychiatric and cognitive decline, over a 3-year period. We first looked at the annual rate of decline of a group of HD patients taking Antidopaminergic medication (n=466) compared with an untreated matched group (n=466). The groups were matched on specified clinical variables using propensity score matching. Next, we studied a separate group of HD patients who were prescribed such medications part way through the study (n=90) and compared their rate of change before and after the drugs were introduced and compared this to a matched control group. Results We found that HD patients taking Antidopaminergic medication had a slower progression in chorea and irritability compared with those not taking such medications. However, this same group of patients also displayed significantly greater rate of decline in a range of cognitive tasks. Conclusion In conclusion we found that Antidopaminergic treatment is associated with improvements in the choreic movements and irritability of HD but worsens cognition. However, further research is required to prospectively investigate this and whether these are causally linked, ideally in a double-blind placebo-controlled trial.

Tsuyoshi Kondo - One of the best experts on this subject based on the ideXlab platform.

  • Combination of dopamine D2 receptor gene polymorphisms as a possible predictor of treatment-resistance to dopamine antagonists in schizophrenic patients.
    Progress in neuro-psychopharmacology & biological psychiatry, 2003
    Co-Authors: Tsuyoshi Kondo, Kazuo Mihara, Akihito Suzuki, Norio Yasui-furukori, Sunao Kaneko
    Abstract:

    Both the A1 allele carriers of TaqI A and Del allele noncarriers of −141C Ins/Del for dopamine D2 receptor (DRD2) gene polymorphisms have been reported to have a lowered DRD2 density. The present study aimed to examine whether the combinations of these two DRD2 gene polymorphisms predict treatment response to Antidopaminergic agents in schizophrenic patients. Subjects consisted of 49 acutely exacerbated schizophrenic inpatients treated with bromperidol (30 cases, mean dose±S.D.: 11.4±4.8 mg/day) or nemonapride (19 cases, 18 mg/day). Clinical symptoms were evaluated using Brief Psychiatric Rating Scale (BPRS) before and 3 weeks after the treatment. DRD2 genotypes were determined using a polymerase chain reaction method. The A1 noncarriers with a Del allele showed poorer percentage improvement in anxiety–depression symptom after 3-week treatment (n=9, 7.3±42.9%) than A1 carriers without Del alleles (n=25, 62.4±38.0%) or A1 noncarriers without Del alleles (n=10, 65.4±29.2%). However, these preliminary results should be replicated in further research with a larger number of the subjects in each haplotype subgroup.

  • prolactin response to zotepine in schizophrenic patients
    Human Psychopharmacology-clinical and Experimental, 1993
    Co-Authors: K Otani, Hiroshi Sasa, Hisashi Higuchi, Tsuyoshi Kondo, Sunao Kaneko, Masayuki Ishida, Yutaka Fukushima
    Abstract:

    The prolactin response to an antipsychotic drug zotepine, which has both Antidopaminergic and antiserotonergic effects, was studied in 24 inpatients suffering from schizophrenia. The daily dose was 100 mg in the first week, and 200 mg for the next three weeks. The mean serum concentrations of prolactin at the daily dose of 200 mg, but not 100 mg, were significantly higher than that before treatment. The δ prolactin (the change from the pretreatment concentration) was significantly correlated with zotepine concentrations at each week. At low zotepine concentrations, patients with high pre-treatment prolactin concentrations showed negative δ prolactin. The present study thus suggests that at high concentrations zotepine shows predominantly Antidopaminergic effects, while at low concentrations its antiserotonergic effects are predominant and/or it acts as a dopamine agonist.

Yutaka Fukushima - One of the best experts on this subject based on the ideXlab platform.

  • prolactin response to zotepine in schizophrenic patients
    Human Psychopharmacology-clinical and Experimental, 1993
    Co-Authors: K Otani, Hiroshi Sasa, Hisashi Higuchi, Tsuyoshi Kondo, Sunao Kaneko, Masayuki Ishida, Yutaka Fukushima
    Abstract:

    The prolactin response to an antipsychotic drug zotepine, which has both Antidopaminergic and antiserotonergic effects, was studied in 24 inpatients suffering from schizophrenia. The daily dose was 100 mg in the first week, and 200 mg for the next three weeks. The mean serum concentrations of prolactin at the daily dose of 200 mg, but not 100 mg, were significantly higher than that before treatment. The δ prolactin (the change from the pretreatment concentration) was significantly correlated with zotepine concentrations at each week. At low zotepine concentrations, patients with high pre-treatment prolactin concentrations showed negative δ prolactin. The present study thus suggests that at high concentrations zotepine shows predominantly Antidopaminergic effects, while at low concentrations its antiserotonergic effects are predominant and/or it acts as a dopamine agonist.