1.Sedative and hypnotic effects of zolpidem on insomnia model mice induced by hypoxia
Huanhuan LIANG ; Lin XU ; Gang YU ; Ruibin SU ; Mingyuan LI
Chinese Journal of Pharmacology and Toxicology 2024;38(2):81-88
OBJECTIVE To study the sedative and hypnotic effects of zolpidem and the content of amino acid neurotransmitters in the thalamus and hypothalamus after treatment with zolpidem.METHODS Experiments on the loss of righting reflex(LORR)induced by the upper-threshold dose pentobarbital sodium(50 mg·kg-1,ip)were conducted to establish a hypoxic insomnia model in mice by simulating an altitude of 5500 m.Based on this model,the synergistic effect of zolpidem(0.33,1,3,9 and 27 mg·kg-1,ip)and the subthreshold(20 mg·kg-1,ip)and upper-threshold pentobarbital sodium,as well as the sedative hypnotic effect of zolpidem(10,13,17,20,23,30 and 40 mg·kg-1,ip)were evaluated via the LORR in normoxic and hypoxic environments.One hour after ip given zolpidem,the levels of glutamic acid(Glu)and γ-aminobutyric acid(GABA)in the thalamus and hypothalamus of mice in either environment were determined by the high-performance liquid chromatography(HPLC)with fluorescence detection.RESULTS One-day treatment with hypoxia significantly shortened the duration of LORR induced by the upper-threshold dose pentobarbital sodium.Compared with normoxia vehicle and hypoxia induced insomnia vehicle groups,zolpidem 9 and 27 mg·kg-1 significantly shortened the latency to LORR(P<0.01,P<0.05)and prolonged duration of LORR induced by subthreshold and upper-threshold pentobarbital sodi-um(P<0.01,P<0.05).The median effective dose(ED50)of LORR induced by zolpidem was 16.21 and 20.55 mg·kg-1 in normoxic and hypoxic environments,respectively.The results of neurotransmitter level detection showed that Glu contents in the thalamus and hypothalamus and the ratio of Glu/GABA in the hypothalamus were decreased after treatment with zolpidem 40 mg·kg-1 in a normoxic environment(P<0.01,P<0.05).Compared with the normoxia control group,Glu content and the ratio of Glu/GABA in the hypothalamus were significantly increased after treatment with hypoxia(P<0.01,P<0.05),and zolpidem 40 mg·kg-1 could reverse their elevation.CONCLUSION The sedative-hypnotic effect of zolpidem is weakened in a hypoxic environment,and the effect of zolpidem on the levels of Glu and GABA in the hypothalamus may play an important role in the sedative-hypnotic effect of zolpidem.
2.Psychological dependence liability of gaboxadol in two-bottle free-choice model in mice
MUHEYATI ALAI ; Yu ZHAO ; Gang YU ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(2):97-104
OBJECTIVE To evaluate the psychological dependence of the extrasynaptic GABAA receptor(GABAAR)agonist gaboxadol and compare it with the synaptic GABAAR modulator midazolam in the two-bottle free-choice model of mice.METHODS ① Male C57BL/6J mice were ig administered with vehicle,midazolam(59.0,73.7,92.2,115.2,144.0 and 180.0 mg·kg-1)or gaboxadol(8.4,10.5,13.1,16.4,20.5,25.6 and 32.0 mg·kg-1),and the loss of righting reflex was observed.The median effective dose(ED50)was obtained from the dose-response curve.② A two-bottle free-choice model was used to find out whether gaboxadol and midazolam induced preference behavior in mice.The mice were divided into normal control,gaboxadol or midazolam groups.During the habituation stage(the first day to the third day,D1-D3),both test and vehicle bottles contained water.During the trail stage(D4-D5),4%sucrose solution was provided in both bottles.During the test stage(D6-D15),test bottles contained vehicle,gaboxadol(3.9×10-6 mol·L-1)or midazolam(1.4×10-5 mol·L-1)in sucrose solu-tions,while other bottles contained the corresponding vehicle in sucrose solutions.Bottles were placed on the two sides of the home cage,to which mice had free access,and their consumption from each bottle was recorded daily.Total consumption,accumulated daily consumption,relative consumption,and accumulated relative consumption during the test stage were calculated.The weight of the mice was also recorded.RESULTS ① Midazolam and gaboxadol dose-dependently increased the rate of loss of right reflex in mice,with ED50 of 105.3 mg·kg-1(95%CI:96.4-115.2 mg·kg-1,R2=0.9796),13.7 mg·kg-1(95%CI:12.6-15.0 mg·kg-1,R2=0.9773),respectively.② Compared with the normal control group,there was no significant difference in the total consumption in the gaboxadol and midazolam groups.Compared to the vehicle bottles,the daily consumption from test bottles in the midazolam group increased significantly on D11-D15 of the test stage(P<0.05),while daily consumption from gaboxadol test bottles was significantly higher than that of vehicle bottles(P<0.01).Compared with the normal control group,the daily relative consumption in the gaboxadol group was significantly increased on D9(P<0.05),and the accumulative relative consumption was significantly higher than in the normal control group(P<0.01).There was no significant change in body weight across the groups over the test stage.CONCLU-SION Like midazolam,gaboxadol exhibits psychological dependence potential in a two-bottle free-choice model.
3.Design,synthesis and activity evaluation of novel 5-HT2A receptor antagonists
Luobing HAN ; Shiyang SUN ; Yu ZHAO ; Gang YU ; Ruibin SU ; Zhibing ZHENG ; Song LI
Military Medical Sciences 2024;48(10):767-777
Objective To discover 5-HT2A receptor antagonist molecules with novel structures and explore their structure-activity relationship through structure-and mechanism-based drug design,synthesis and activity evaluation.Methods The way in which pimovanserin interacted with 5-HT2A receptor was analyzed via molecular docking,molecular dynamics simulation and binding free energy calculations.Based on the results of this study,the 5-HT2A receptor antagonist target compounds with novel structures were designed using pimovanserin as the lead molecule.According to the structures of target compounds,corresponding synthetic routes were designed.The heterocyclic methylamine intermediates were obtained by reductive amination or reduction reaction from heterocyclic formaldehyde or heterocyclic methanonitrile before being reacted with 4-(4-fluorobenzylamino)-1-methylpiperidine to obtain the target compounds using CDI urea synthesis method.The inhibitory activity of the target compounds against 5-HT2A receptor was tested at the cellular level,and the anti-hallucinogenic effects of the target compounds were tested in the mouse head twitch response model.Results Twelvenovel compounds were synthesized and their structures were confirmed by HR-MS,1H-NMR and 13C-NMR.The results of the activity assay showed that compounds 6a,6c and 6d exhibited better 5-HT2Areceptor inhibitoryactivity with IC50 values of 120,152 and 285 nmol/L,respectively while compounds 6c and 6d exhibited better anti-hallucinogenic activity in mice with inhibition rates of 97.0%and 82.9%(10 mg/kg),respectively.Conclusion The novel compound 6c and 6d have shown strong 5-HT2A receptor inhibitoryactivity and anti-hallucinogenic activity and deserve more research.Structure-activity relationship analyses of target compounds indicate that the repulsion of the heterocyclic ring with basic N atoms and the accommodation of the heterocyclic ring without basic N atoms by the side extended pocket of the 5-HT2A receptor could significantly affect the ex vivo and in vivo effects of antagonists.
4.Effect of 2,5-dimethoxy-4-methylamphetamine on low γ and high-frequency oscillations in rat orbitofrontal cortex
Yan WANG ; Kaili JIANG ; Xiaoyan LIU ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(5):335-343
OBJECTIVE To investigate possible electrophysiological mechanisms of psychogenic disorders caused by the classical hallucinogen 2,5-dimethoxy-4-methylamphetamine(DOM).METHODS Microelectrode array implantation in the orbitofrontal cortex(OFC)was performed in adult male SD rats.After one week of recovery from surgery,the drugs were administered intraperitoneally to rats in the following order:DOM(0.5,1.5,and 3.0 mg·kg-1),DOM 3.0 mg·kg-1+ketanserin 1.0 mg·kg-1,DOM 3.0 mg·kg-1+SB242084 3.0 mg·kg-1,ketanserin 1.0 mg·kg-1,SB242084 3.0 mg·kg-1.Saline was given as a control group before each drug treatment.The changes of field potential(LFP)in OFC were recorded by the Plexon in vivo multichannel recording system.There was one week of washout of drugs between medications.RESULTS DOM(0.5,1.5 and 3.0 mg·kg-1)increased the power of high frequency oscillations(HFO,P<0.05)but decreased the power of low γ oscillations(P<0.05,P<0.01)in OFC compared to saline.Ketanserin(1.0 mg·kg-1)antagonized DOM induced changes in low γ oscilla-tions(P<0.01)and HFO(P<0.05)power,but SB242084(3.0 mg·kg-1)did not.CONCLUSION DOM can cause such psychoneurological disorders as hallucinations,which may be related to the power decrease of low γ oscillations and increase of HFO in OFC by acting at 5-HT2A receptors.
5.Neuronal type screening and identification of head twitch responses induced by mescaline
Yuanyuan WANG ; Peilan ZHOU ; Haitao YAN ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(5):353-359
OBJECTIVE To investigate the types of neurons that influence the head twitch response(HTR)induced by 5-hydroxytryptaminergic(5-HTergic)psychedelic mescaline in mice.METHODS①Adult male C57BL/6J mice were randomly divided into the normal control group and mescaline(1.56,3.125,6.25,12.5,25 and 50 mg·kg-1)groups,with 15 mice in each group.The drugs of the corresponding groups were ip given,and the HTR frequency of mice was recorded for 30 min.② 5-HT 2A receptor(5-HT2AR)gene bilateral LoxP homozygous mice(5-HT2A flox/flox)were hybridized with calmodulin depen-dent protein kinaseⅡα cyclization recombination enzyme positive(CaMKⅡαcre/+),parvalbumin(PV)cre/+,somatostatin(SOM)cre/+or vasoactive intestinal peptide(VIP)cre/+mice to obtain 5-HT2A R conditional knockout(cKO)mice(5-HT2AΔCaMKⅡα,5-HT2AΔPV,5-HT2AΔSOM and 5-HT2AΔVIP).Each type of cKO mice was randomly divided into the normal control group and mescaline 12.5 mg·kg-1 group,with 15 mice in each group.The drugs of the corresponding groups were ip given before the HTR frequency of mice within 30 min was recorded.③ Each type of cKO mice was randomly divided into the normal control group and mescaline 12.5 mg·kg-1 group,with 12 mice in each group.After receiving the corresponding drug via ip,they were placed in a spontaneous activity test box for 30 minutes and their activity levels were recorded.RESULTS ① Compared with the normal control group,mescaline 3.125,6.25,12.5 and 25 mg·kg-1 significantly increased the HTRs of mice(P<0.05,P<0.01).② Among the different neuronal types of 5-HT2AR cKO mice,only 5-HT2A ΔCaMKⅡα mice had no difference in HTR frequency between the normal control group and the mescaline 12.5 mg·kg-1 group.In 5-HT2AΔPV,5-HT2AΔSOM and 5-HT2AΔVIP mice,the HTRs of mice in the mescaline 12.5 mg·kg-1 group were significantly increased(P<0.01)compared with the normal control group.③ There was no difference in spontaneous activity between the normal control group and the mescaline 12.5 mg·kg-1 group of all cKO mice.CONCLU-SION Pyramidal neurons are involved in mediating the induction of mescaline on HTRs in mice.
6.Progress of 5-HT2A receptor antagonists in treatment of hallucinatory symptoms induced by neuropsychiatric disorders
Yu ZHAO ; Aibing CHEN ; Gang YU ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(5):384-391
Neuropsychiatric disorders such as Parkinson disease,Alzheimer disease,and schizo-phrenia may induce hallucinations,delusions,and other psychiatric symptoms during the course of disease development.These symptoms are highly prevalent and difficult to cure,and have a impact on the lives of patients.Classical antipsychotic drugs such as chlorpromazine,sulpiride and perphenazine can con-trol related symptoms,but they can also cause uncontrollable extrapyramidal system reactions and side effects such as hyperprolactinemia.In recent years,it has been found that non-classical antipsy-chotics such as olanzapine,clozapine,risperidone and pimovanserin can treat hallucinatory symptoms in neuropsychiatric disorders by antagonising the 5-hydroxytryptamine 2A(5-HT2A)receptor,or by antago-nising both the 5-HT2A receptor(strong)and the dopamine 2(D2)receptor(weak).In preclinical studies,non-classical antipsychotic drugs have shown great therapeutic effects against hallucination induced by multiple factors.Clinical studies have confirmed that these drugs improve psychotic symptoms(mainly hallucinations and delusions)significantly.In patients who are insensitive or tolerant to clozapine and risperidone,pimavanserin still shows therapeutic effects.At the same time,the incidence and severity of adverse reactions to non-classical antipsychotic drugs are reduced,and they are well tolerated.This article reviews the research progress in the role of 5-HT2A receptor antagonists in attenuating hallucino-genic symptoms so as to provide reference for the design and development of new therapeutic drugs.
7.Establishment of cells stably co-expressing with α1A-adrenergic receptor and enhanced green fluorescent protein tagged nuclear factor of activated T cells 2
Xiaoxuan WANG ; Yulei LI ; Peilan ZHOU ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(8):587-594
OBJECTIVE To establish the cells stably co-expressing α1A-adrenergic receptor(α1A-AR)and enhanced green fluorescent protein(EGFP)tagged nuclear factor of activated T cells 2(NFAT2)(EGFP-NFAT2)in U2OS cells.METHODS ① The pcDNA3.1-α1-AR-3×FLAG recombinant plasmid was transfected into U2OS-EGFP-NFAT2 cells.The transfected cells were selected by hygromycin B(Hygro-B,200 mg·L-1),and screened by EGFP-NFAT2 nuclear translocation assay after α1A-AR agonist norepinephrine(NE)treatment of 30 min.② The mRNA and protein expression levels of α1A-AR in the selected U2OS-EGFP-NFAT2-α1A-AR cells were examined by real-time quantitative PCR(RT-qPCR)and Western blotting.③ U2OS-EGFP-NFAT2-α1A-AR cells were treated with NE(10-8-10-5 mol·L-1)or dexmedetomidine(DMED,10-8.8-10-5 mol·L-1),respectively,for 30 min.EGFP-NFAT2 nuclear translo-cation was detected by high throughout screening assay.④ The U2OS-EGFP-NFAT2-α1A-AR cells were divided into the solvent control group,α1-AR antagonist naftopidill(1 μmol·L-1)group,NE(1 μmol·L-1)group and naftopidill+NE(co-incubation with naftopidill 1 μmol·L-1 and NE 1 μmol·L-1)group,α2-AR antagonist atipamezole(ATI,0.1 μmol·L-1)group,α 2-AR agonist DMED(0.1 μmol·L-1)group,and ATI+DMED(co-incubation with ATI 1 μmol·L-1 and DMED 0.1 μmol·L-1)group.The drug incubation time was 30 min.EGFP-NFAT2 nuclear translocation was abserved via a high throughout screening system to validate the α1A-AR function in U2OS-EGFP-NFAT2-α1A-AR cells.RESULTS ① There were 58 cell strains expressing α1A-AR in U2OS-EGFP-NFAT2 cells by EGFP-NFAT2 nuclear translocation assay.Among these cells,cells No 50 had the highest nuclear translocation function.The α1A-AR mRNA expression of cells No 50 in 5-20 generations were detected by RT-qPCR and were about 500-800 times that of U2OS-EGFP-NFAT2 cells.② The protein band of α1A-AR was also detected in cells No 50,but no band of α1A-AR was detected in U2OS-EGFP-NFAT2 cells by Western blotting.③ NE and DMED increased the relative translocation nuclear index in U2OS-EGFP-NFAT2-α1A-AR cells with ED50 5.94×10-7 and 6.15×10-8 mol·L-1,respectively.④ EGFP-NFAT2 nuclear translocation was significant in U2OS-EGFP-NFAT2-α1A-AR cells after NE addition compared with the solvent control or the naftopidill groups(P<0.01).The EGFP-NFAT2 nuclear translocation in the naftopidill+NE group was significantly decreased compared with the NE group(P<0.01).DMED significantly increased the EGFP-NFAT2 nuclear translocation compared with solvent control or the ATI groups(P<0.01).The EGFP-NFAT2 nuclear translocation in the ATI+DMED group was similar to that of the DMED group.The EGFP-NFAT2 nuclear translocation in the naftopidill+DMED group was decreased significantly compared with the DMED group(P<0.01).CONCLUSION U2OS-EGFP-NFAT2-α1A-AR cells stably co-exrepssing α1A-AR and EGFP-NFAT2 are established,which can be used for high throughout screening of biased chemicals and studies on the mechanism of α1A-AR.
8.A rapid detection method for activated RhoA proteins based on high-content image anylysis
Yanan ZHOU ; Ying QU ; Shaowen WANG ; Yi SUN ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2024;38(11):839-845
OBJECTIVE To develop a rapid method for detection of activated RhoA protein using the high content imaging system(HCIS).METHODS Hek293 or CHO cells were seeded in 96-well plates and subjected to starvation treatment after attachment.Hek293 cells were incubated with nocodazole,a RhoA agonist,at concentrations of 0(vehicle control),10-11,10-10,10-9,10-8,10-7,10-6,10-5 and 10-4 mol·L-1 for 3,10 and 30 min respectively.CHO cells were incubated with nocodazole,lyso-phosphatidic acid(LPA)and calpain at the same concentrations for 3,10 and 30 min respectively.Imme-diately after incubation,the cells were fixed with 3.7%formaldehyde solution and stained using Hoechst and rhodamin phallodin at room temperature and protected from light.Images were captured using HCIS and analyzed statistically.Changes in the mean fluorescence intensity(MFI)were used to assess the activation of RhoA protein by the drugs.RESULTS Compared with the vehicle control group,the MFI of Hek293 cells treated with nocodazole for 3 min significantly increased at concentra-tions ranging from 10-10 to 10-6 mol·L-1(P<0.01).When the treatment duration was extended to 30 min,MFI elevations were observed at concentrations between 10-10 and 10-4 mol·L-1(P<0.01),indicating the activation of RhoA protein.In CHO cells,compared with the vehicle control group,MFI was increased after 10-10-10-6 mol·L-1 nocodazole treatment of 10 min and 30 min(P<0.05,P<0.01).Similarly,MFI was also increased under various conditions of LPA and calpeptin treatment.LPA 10-11-10-4 mol·L-1 treatment of 3 min and 10-11,10-8-10-4 mol·L-1 treatment of 10 min and 10-11-10-9,10-7,10-6,10-4 mol·L-1 treatment of 30 min all resulted in an elevated MFI(P<0.05,P<0.01).Calpeptin 10-11-10-6,10-4 mol·L-1 treatment of 10 min and 10-11 and 10-4 mol·L-1 treatment of 30 min also resulted in an elevated MFI(P<0.05,P<0.01).These results indicated that RhoA protein was effectively activated.CONCLUSION A method for rapid detection of RhoA protein activation has been established,which is capable high-throughput,rapid and easy detection of activated RhoA protein.
9.Practice of online teaching method of combining CBL and RadiAnt DICOM Viewer for undergraduate medical students in radiology department
Ruibin HUANG ; Shuyan SU ; Liujiang CHEN ; Xiaoli CHEN ; Xiaohuan YANG ; Yuan LIU
Chinese Journal of Medical Education Research 2023;22(9):1356-1360
Clinical undergraduates generally have the following problems during their radiology internship: short internship period, low motivation, teachers using traditional teaching mode, and insufficient hardware and software facilities for image reading. In this study, RadiAnt DICOM Viewer and case-based learning (CBL) model were applied in online practice teaching for clinical undergraduates in the radiology department, which achieved good results. The results showed that the clinical undergraduates had a pass rate of 91.18% (124/136) in the image reading quiz and a mean score of (85.71±10.99) in the in-class quiz, with a pass rate of 91.91% (125/136). The satisfaction survey showed that 84.56% (115/136) of the students were more satisfied with the application of RadiAnt DICOM Viewer in image reading teaching; 80.88% (110/136) of the students expressed more interest in radiology after this training course; 90.44% (123/136) of the students thought that online practice teaching of radiology is feasible.
10.Contrasting effects of DOM and lisuride on impul-sive decision-making in delay discounting task
Kaili JIANG ; Xiaoyan LIU ; Ruibin SU
Chinese Journal of Pharmacology and Toxicology 2023;37(7):532-532
OBJECTIVE The 5-HT2A receptor is the major target of classic hallucinogens.Both DOM(2,5-dimethoxy-4-methylamphetamine)and lisuride act at 5-HT2A receptors,and lisuride shares comparable affinity with DOM and acts as a partial agonist at 5-HT2A recep-tors.However,not like DOM,lisuride lacks hallucinogenic properties.Impulsive decision-making refers to the prefer-ence for an immediate small reinforcer(SR)over a delayed large reinforcer(LR).The current study aims to compare the effects of DOM and lisuride on impulsive decision-making and further to investigate the possible receptor mechanisms responsible for the actions of the two drugs.METHODS Impulsive decision-making was evaluated in male Sprague-Dawley rats by the percent-age of choice for the LR in delay discounting task(DDT).Delay to the LR changed in an ascending order(0,4,8,16,and 32 s)across one session.RESULTS DOM(0.3 and 0.5 mg·kg-1)increased impulsive decision-making,and the effects of DOM(0.5 mg·kg-1)was blocked by the 5-HT2A receptor antagonist ketanserin(1.0 mg·kg-1)rather than the 5-HT2C receptor antagonist SB-242084(1.0 mg·kg-1).Contrarily,lisuride(0.1,0.3 and 0.5 mg·kg-1)decreased impulsive decision-making.The effects of lisu-ride(0.3 mg·kg-1)were not antagonized by ketanserin(1.0 mg·kg-1),selective 5-HT1A antagonist WAY-100635(1.0 mg·kg-1)or selective dopamine D4 receptor antagonist L-745870(1.0 mg·kg-1),but were attenuated by the selec-tive dopamine D2/D3 receptor antagonist tiapride(40 mg·kg-1).CONCLUSION DOM and lisuride have contrasting effects on impulsive decision-making via distinct recep-tors.DOM-induced increase of impulsivity is mediated by the 5-HT2A receptor,while lisuride-induced inhibition of impulsivity is regulated by the dopamine D2/D3 receptor.

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