AIM To investigate the effects of polydatin on mouse hepatocyte injury induced by hydrogen peroxide(H 2O 2). METHODS Mouse hepatocytes were prepared. SOD activity, MDA content, GSH level, GSH-px activity, glutamic-pyruvic transaminase (ALT), nitric oxide(NO) and nitric oxide synthase(NOS) were determined with different method, respectively. RESULTS After 1 h incubation, the mouse hepatocytes with various concentrations of polydatin (0 05, 0 1, 0 5, 1, 2, 4 mmol?L -1 ), significantly decreased the contents of NO and MDA, inhibited the NOS activity, increased the activities of SOD and GSH-px, suppressed the consumption of GSH, and reduced the elevated ALT level in the supernatant induced by H 2O 2. CONCLUSION Polydatin can protect hepatocytes from oxidative injury induced by H 2O 2.

Aim To study the effect of rhynchophylline on NMDA receptor 2B subunit(NR2B) mRNA expression in the nucleus accumbens(NAc) and amygdala(Amy) of amphetamine-induced condictioned place preference(CPP) rats.Method 56 male SPF grade Sprague-Dawley rats were randomly divided into control group,amphetamine-induced model group,model group with ketamine,model group with low,middle,high dose of rhynchophylline,and control group with rhynchophylline(n=8 for each group) The time of rats' staying in white compartment was measured in the 5th day,then NR2B mRNA expression in NAc and Amy of each rat was detected with in situ hybridization technology.Results The rats exhibited CPP after treated with 2 mg?kg-1?d-1 amphetamine for 4 d.Ketamine and rhynchophylline eliminated CPP effect,and the effect of rhychophylline showed a dose-dependence.In amphetamine-induced model group,NR2B mRNA expression in NAc and AMY of rats was significantly increased.Ketamine,middle and high dose of rhynchophylline blocked the increase of NR2B mRNA expression induced by amphetamine.Rhynchophylline had no effect on the basal level of RN2B mRNA expression in normal rats.Conclusion Inhibition of NR2B mRNA expression in NAc and AMY may contribute to the antagonistic effect of rhychophylline on amphetamine-induced CPP.

The effect of dexamethason ( Dex ) on the rabbit platelet aggregation and release was studided. The results were showed that the platelet aggregation and release induced by collagen were inhibited markedly by Dex, TXA2 production of platelets also reduced, but the platelet activation induced by AA was not affected by Dex. The results were further showed that the PLA2 activity was depressed by Dex, and the action of Dex can be antagonized partly by increase of extracellular Ca2+, it suggests that Dex inhibited the activity of PLA2 with the reduction of Ca2+ inflow into cell. The activity of CaM and AC, the production of cAMP and cGMP were not affected by Dex.

AIM To explore the effects of sinomenine (Sin) on psychic dependence induced by morphine (Mor) in mice and its relation to the cAMP content of the cerebral cortex. METHODS A biased procedure induced the strong place preference. The effect of Sin (10, 30, 60 mg?kg -1 , ip) on the rewarding property of morphine was observed in a conditioned place preference(CPP) paradigm in mice,at the same time, the change of cAMP content in cerebral cortex was measured by the radioimmunoassay(RIA). RESULTS Sin significantly shortened the time of staying in morphine-pair compartment and lowered the cAMP level of mice. CONCLUSION Sin could attenuate effects of psychical dependence induced by Mor, its mechanism may be related to decrease of cAMP level in the brain, and Sin did not display psychical dependence in the experiment.

Objective To investigate the changes of monoamine neurotransmitters of the brain in two tat models of morphine dependence,and to explore the effects of sinomenine on morphine dependence.Methods A physical dependent rat model was established with morphine at a gradually increasing dosage and the withdrawal syndrome was scored after naloxone precipitation.The conditioned place preference(CPP)in rats induced by morphine was used to investigate psychic dependence in rots.Contents of norepinephrine(NE),dopamine(DA)and serotonin(5-HT)in hypothalamus of rats were assayed with a fluorescent method.Results 1.In naloxone precipitated withdrawal test of in morphine-dependent rats,after morphine withdrawal,the rats presented marked with drawal symptoms and signs,their withdrawal scores were significantly increased,and the levels of NE and 5-HT in hypothalamus of the rats were significantly increased than the control group Ⅰ(7.07±1.406μg/g wet tissue and 1.15±0.346 μg/g wet tissue,respectively,P<0.01),but the content of DA was markedly reduced than the control group Ⅰ(0.28±0.121 μg/g wet tissue,P<0.05).2.In CPP model,morphine caused a marked place preference in rats and the levels of DA and 5-HT in hypothalamus were significantly increased than the control group Ⅱ(1.13±0.359 μg/g wet tissue and 1.23±0.343μg wet tissue,respectively,P<0.01),but the content of NE was not significantly changed(3.28±1.098 μg/g wet tissue,P>0.05).Sinomenine could significantly inhibit the withdrawal syndrome and development of CPP induced by morphine in rats,and could suppress the rising of monoamine neurotransmitters of the brain in two morphine dependent models in rats.Conclusion In the physical dependent model induced by morphine in rats,the rising of NE and 5-HT in the rat brain were significant,but in CPP model induced by morphine in rats,the levels of DA in the rat brain were enhanced predominately.Sinomenine could inhibit the withdrawal syndrome and development of CPP in rats,and regulate and improve the function of monoamine nerve system.

Objective To investigate the changes of monoamine neurotransmitters of the brain in physical dependence induced by morphine in rats.Methods A physical dependent rat model was established with morphine in a gradually in creasing doses and the withdrawal syndrome was scored after naloxone precipitation.The conditioned place preference(CPP)in rats induced by morphine was used to investigate psychic dependence in rats.Contents of norepinephrine(NE0,dopamine(DA)and serotonin(5-HT)in hypothalamus of rats were assayed with a fluorescent method. Results (1)In naloxone-precipitated withdrawal test of morphine-dependent model rats,after morphine had been withdrawn,morphine-abstinent rats presented marked withdrawal symptoms and signs,their withdrawal scores were significantly increased,and the levels of NE and 5-HT in the rat brain were obviously enhanced,but the content of DA was reduced.(2)In CPP test,morphine caused a marked place preference in rats and the levels of DA and 5-HT in the rat brain were obviously enhanced,but the content of NE was reduced.Conclusiion Morphine dependence development and withdrawal are closely connected with monoamine neurotransmitters in CNS.In the physical dependent model induced by morphine in rats,the rising of NE and 5-HT in the rat brain were significant,but in psychic dependent model induced by morphine in rats,the levels of DA in the rat brain were enhanced p-redominately.

Objective To establish a methamphetamine-dependent model in zebrabfish.Methods On the basis of conditioned place preference (CPP) in drug-dependent experiment,place preference box for zebrafishes was designed.According to the natural characteristics of zebrafishes,their preference side and non-preferred side were determined.After intraperitoneal injection of methamphetamine,zebrafishes were placed in non-preferred side(drug box).After intraperitoneal injection of normal saline,zebrafishes were placed in preference side (non-drug box).CPP training was five days and then the methamphetamine-induced place preference in zebrafish were observed.Results After five days training,the staying time of zebrafishes of control group in drug box was not significantly lengthened to compared with before training(.( 287.5 ± 80.18 ) s,(276.3 ± 85.04) s),P＞ 0.05 ).The staying time of zebrafishes of model group in drug box was markedly extended after training.In comparison with before training or control group,the significant differences were observed ( (465.5 ± 113.49 ) s,( 247.9 ±95.62)s,(276.3 ±85.04)s,P＜0.01).Conclusion Methamphetamine can induce conditioned place preference in zebrafishes.The CPP model in zebrafish established in this study can be used as a new animal model in drug dependence.

Amphetamine-type stimulants ( ATS ) , a group of new-type synthetic drugs mainly in psychological dependence, are abused more and more severely in recent years. MicroRNAs ( MiRNAs ) are an important class of endogenous non-coding small RNAs that mediate posttranscriptional negatively regulation of gene expression by targeting specific mRNA sequences to in-hibit the translation of mRNAs or degrade the expression of mR-NAs. ATS can induce the changes in the expression of miRNAs in addiction-related brain regions which directly involve in the regulation of ATS-induced addictive behaviors. Therefore, to study the regulatory role of miRNAs in ATS-induced addiction has important implications for dependent mechanisms of new-type drugs and the discovery of the new targets of drug actions.

Objective To study changes of AMPA receptors expression in nucleus accumbens and hypothalamus of methamphetamine dependent rats,and the therapeutical effect of rhynchophylline.Methods SPF male rata were randomly divided into normal control group,model group of methamphetamine,low dose of rhynchophylline group and high dose of rhynchophylline group(n=8 in each group).Experiment of conditioned place preference(CPP)was used to build the model of methamphetamine dependent rata.Western blotting was used to examine the changes of GluR2/3 subunits expression.The time of staying in drug-paired compartment of rats was used independent-samples t test to gather statistics,and the photodensity of proteinum strap was used One-Way ANOVA to gather statistics.Results Compare with rats in normal control group(the time of staying in drug-paired compartment of rats was(383.00±38.20)s),the rats produced CPP after treated with methamphetamine(the time of staying in drug-paired compartment of rats was(536.20±57.49)s),and low(30mg/kg) and high (60 ms/kg)dose of rhynchophylline(the time of staying in drug-paired compartment of rats were(299.80±15.96)s and(189.40±59.02)s)both could eliminate CPP effect.Compare with rats in normal control group (the ratio of value of average gray scale were(0.54±0.04)INT·mm~2 and (0.70±0.04)INT·mm~2),GluR2/3 subunits expression in nucleus aecumbens increased significantly in model group(the ratio of value of average gray seale was(0.89±0.03)INT·mm~2)and low dose of rhynchophylline group(the ratio of value of average gray seale was (0.93±0.03)INT·mm~2,P<0.01),which decreased significantly in hypothalamus(the ratio of value of average gray scale were (0.53±0.03)INT·mm~2 and (0.52±0.02)INT·mm~2,P<0.01).But GluR2/3 subunits expression in nucleus accumbens and hypothalamus of rats in high dose of rhynchophylline group(the ratio of value of average gray scale were (0.57±0.06)INT·mm~2 and (0.65±0.01)INT·mm~2) just liked the expression of normal control group(P>0.05).Conclusion GluR2/3 subunits expression of methamphetamine-induced CPP rats increased in nucleus accumbens but decreased in hypothalamus.High dose of rhynchophylline can reverse such changes and rebound the expression to normal level.