Journal Detail Information

1

Cite

Share

Effect of methylamphetamine on action potential and delayed rectifier potassium current in guinea-pig ventricular myocytes

Yanming ZHOU ; Ruobing LIANG ; Xiuli ZHAO ; Minghui ZHANG ; Feng WU ; Bo ZHU

Chinese Journal of Pharmacology and Toxicology.2010;24(6):449-454. doi:10.3867/j.issn.1000-3002.2010.06.001

OBJECTIVE To explore the mechanism of methylamphetamine (MA) on heart toxicity. METHODS The effects of MA on delayed rectifier potassium current (IK) and action potential (AP) were analyzed in isolated decreased AP from 121.6 to 106.0 mV and delayed the action potential duration (APD), but had no effect on the resting potential. The 10%, 25%, 50%, 75% and 90% of APD (APD10, APD25, APD50, APD75 and APD90)inhibited the membrane potential of rapidly activating delayed rectifier potassium current (IKr) and slowly activating delayed rectifier potassium current (IKs), downward shifted the Ⅰ -Ⅴ curve, but had no effect on the curve shape and could be partly recovered after flushing. The tail current IKr was blocked concentration-dependently after simiarly inhibited by MA. CONCLUSION MA has inhibitory effects on Ik and AP in ventricular myocytes,which may be one of the possible electrophysiological mechanisms of the cardiac damage caused by MA.

2

Cite

Share

Pre-clinical pharmacokinetics of recombinant heat shock protein 65-mucin 1 fusion protein vaccine

Jing BAI ; Xiao SUN ; Lun OU ; Xiuwen LIU ; Zhongming TANG ; Haifeng SONG

Chinese Journal of Pharmacology and Toxicology.2010;24(3):168-173. doi:10.3867/j.issn.1000-3002.2010.03.002

OBJECTIVE To study the pharmacokinetics of heat shock protein 65-mucin 1 (HSP65-MUC1) recombinant fusion protein vaccine in Macaca mulatta monkeys and tumor-bearing mice. METHODS HSP65-MUC1 was labeled by radioactive isotope 125I. M. mulatta monkeys were randomly divided into sc and iv administration groups. Simultaneously, sc administration group was designed as a multiple dose group in which M. mulatta monkeys were sc given [ 125I] HSP65-MUC1 40 μg·g-1, once every 2 weeks for a total of 3 times. Size exclusion chromatography ( SEC) was used to determine concentrations of HSP65-MUC1 in serum samples. The tumor-bearing mice were randomly divided into 0.5, 1.5, 4, 8 and 24 h groups. Mice were sc given [125I] HSP65-MUC1 550 μg·kg-1, tissues were collected and tissue distribution of [125I] HSP65-MUC1 in tumor-bearing mice was studied using trichloroacetic acid (TCA) precipitation method. RESULTS The absolute bioavailability of [125I]HSP65-MUC1 was 38.33% after M. mulatta monkeys were sc given [125I]HSP65-MUC1. In multiple dose group, concentrations of [125I]HSP65-MUC1 after the third dose administration was compared to that of the first dose administration. The accumulation factor (AUC3/AUC1) was 1.17 ±0.25. Distribution of [ 125I]HSP65-MUC1 was significantly different compared with general polypeptide and protein drugs after sc in tumor-bearing mice. The concentration in lymph nodes was the highest. The concentration in other immune tissues, such as thymus and spleen, were not relatively high, but their declined tendency was slow after reaching the peak concentration (cmax ). However, the concentrations in the serum and some other tissues with a large blood volume, such as the heart, liver, and lung, were relatively low and declined quickly after reaching cmax. Its level in the tumor was not very high. [125 I] HSP65-MUC1 was excreted mainly by the kidneys. CONCLUSION The bioavailability of [125I]HSP65-MUC1 is 38.33% after sc administration in M. mulatta. After multiple-dose administration, the vaccine does not accumulate in the body, whose concentration is the highest in lymph nodes after [1251] HSP65-MUC1 was sc given in tumor-bearing mice, but is not very high in tumor. Besides, the vaccine declined tendency is slow after reaching cmax in immune tissues such as thymus and spleen compared with other tissues with a large blood volume.

3

Cite

Share

Effect of Angong Niuhuang Wan, cinnabar and realgar against lipopolysaccharide-mediated neurotoxicity

Feng ZHANG ; Jie LIU ; Jingshan SHI

Chinese Journal of Pharmacology and Toxicology.2010;24(3):161-167. doi:10.3867/j.issn.1000-3002.2010.03.001

OBJECTIVE To investigate the role of cinnabar and realgar in Angong Niuhuang Wan (AGNH) -produced neuroprotection against lipopolysaccharide ( LPS) -mediated neuronal damage and further explore the corresponding mechanisms. METHODS Primary rat midbrain neuron-glia cultures were used as an in vitro model to investigate effects of AGNH on LPS-mediated degeneration of dopamine (DA) neurons. The experiment was divided into normal control group, LPS model group, LPS + cinnabar (4 and 40 mg·L-1) groups, LPS + realgar (4 and 40 mg·L-1 ) groups and LPS + AGNH (40 and 400 mg·L-1 ) group. Drugs were added 30 min before LPS treatment. After 7 d, dopaminergic neurotoxicity was assessed through the quantification of tyrosine hydroxylase (TH)-positive neurons and morphological analysis of TH-positive neurons; the activation of microglia was evaluated using OX-42 antibody; the gene expression of tumor necrosis factor-α (TNF-α) and induced nitric oxide synthase (iNOS) mRNA in microglia was performed by real-time RT-PCR analysis, and the release of TNF-α and nitric oxide (NO) in the supernatant of neuron-glia cultures was determined respectively by the ELISA and Griess reagent. RESULTS Compared with normal control group, DA neurons in LPS model group decreased by 40% (P <0.05) , microglial activation was induced, the expression of TNF-α mRNA and iNOS mRNA in microglia increased 9 and 2 times, respectively ( P < 0. 05 ) , and subsequent production of TNF-α and NO in the supernatant of neuron-glia cultures increased 20 and 30 times, respectively (P<0.05). Compared with LPS model group, AGNH 400 mg·L-1 and realgar 40 mg·L-1 significantly attenuated LPS-mediated DA neuronal loss by 40% and 30% , respectively (P<0.05) and inhibited activation of microglia and expression of TNF-α mRNA by 61% and 52% (P <0.05). iNOS mRNA was reduced by 58% and 51% (P <0.05 ) in microglia. The subsequent release of TNF-α was reduced by 55% and 43% (P<0.05) and NO reduced by 53% and 34% (P<0.05) in the supernatant of neuron-glia cultures. Cinnabar had no inhibitory effect on LPS-induced changes. CONCLUSION AGNH protects LPS-induced neurotoxicity through its anti-inflammatory properties and realgar might be the key contributor to the neuroprotective action of AGNH, while cinnabar fails to show any neuroprotection.

4

Cite

Share

Research advances of phosphokinases for α-synuclein

Yuanyuan ZENG ; Zhongqin LIANG

Chinese Journal of Pharmacology and Toxicology.2009;23(6):485-489. doi:10.3867/j.issn.1000-3002.2009.06.011

Abnormal aggregation of α-synuclein(α-Syn) is thought to be a key event in the pathogenesis of Parkinson disease (PD). In recent years, it was shown that above 90% of α-Syn deposited in Lewy bodies in brain tissues from patients with PD is phosphorylated, which suggested that α-Syn phosphorylation be connected with the occurrence of PD. Several kinds of phosphokinases can make α-Syn phosphorylated, however the precise roles of these phosphokinases in PD are less clear.

5

Cite

Share

Effects of flavonoids on lipoxygenase activities and their biological functions

Yun HUANG ; Jianan HU

Chinese Journal of Pharmacology and Toxicology.2009;23(6):490-496. doi:10.3867/j.issn.1000-3002.2009.06.012

Lipoxygenase(LOX) is related to emergence and development of many diseases, such as acute and chronic inflammation, atherosclerosis, hypertension and tumor. Therefore, the inhibition of LOX may play an important role in the prevention and treatment of these diseases. Many kinds of flavonoids, such as chalcones, flavonols, flavones and flavanols, have inhibitory effect on 5-LOX, 12-LOX and 15-LOX probably through inhibiting expression of LOX, bonding to the enzyme or reacting with free radicals generated at the active site of the enzyme. Their inhibitory activities are related to their structures. The inhibitory effects of flavonoids on LOX maybe one of mechanisms of flavonoids' some biological functions, such as anti-inflammatory, anti-tumor and reducing the risk of cardiovascular disease and cerebrovascular disease.

6

Cite

Share

Therapeutic effect of bone marrow transplantation on mustard-poisoned mice

Xiaodong KANG ; Jie ZHAO ; Fei NIE ; Kai XIAO

Chinese Journal of Pharmacology and Toxicology.2009;23(6):480-484. doi:10.3867/j.issn.1000-3002.2009.06.010

AIM To study the therapeutic effect of bone marrow transplantation on mustard gas-poisoned mice. METHODS Mustard-poisoned mice model was constructed by injected mustard gas 20 mg·kg~(-1) subcutaneously. At 4 h, 1 d and 2 d after poisoned by mustard gas, the suspended bone marrow cells (106 cells per time) were injected into mice respectively. After poisoned 3, 5, 7 and 10 d, the numbers of leukocyte and marrow nucleated cells were recorded periodically. At the same time, after poisoned 4 h and 1 d by mustard gas, mice in another group were injected granulocyte colony stimulating factor (G-CSF) 74 μg·kg~(-1) combined with transplantation and changes of the cell number were observed. RESULTS Compared with poisoned group without transplantion, leukocyte number in bone marrow transplanted group presented ascending trend, but there was no statistical significance until the 10 d after poisoned. However, the number of marrow nucleated cell increased significantly from the 5th day. After mice injected bone marrow cells combined with G-CSF, leukocyte increased markedly in earlier stage compared with transplantation only. CONCLUTION The bone marrow transplantation has significant effects on improvement of marrow hematogenic system inhibited by mustard gas.

7

Cite

Share

Heterogenous expression and activity analysis of human cytochrome P450 3A4 mutants CYP3A4.3, CYP3A4.4, CYP3A4.5 and CYP3A4.18

Xiaowen WANG ; Su ZENG

Chinese Journal of Pharmacology and Toxicology.2009;23(6):456-463. doi:10.3867/j.issn.1000-3002.2009.06.007

AIM To express recombinant human cytochrome P450 3A4 mutants CYP3A4.3, CYP3A4.4, CYP3A4.5 and CYP3A4.18, and to employ them for in vitro metabolism studies of CYP3A4. METHODS Use Bac-to-Bac baculovirus expression system to recombinant baculovirus carrying cDNA of CYP3A4 mutants CYP3A4.3, CYP3A4.4, CYP3A4.5 and CYP3A4.18. Spodoptera frugiperda 9 (Sf9), cells were co-infected by recombinant viruses of CYP3A4 mutants, human NADPH-P450 oxidoreductase and cytochrome b5 to obtain recombinant proteins CYP3A4.3, CYP3A4.4, CYP3A4.5 and CYP3A4.18 with metabolic activity. RESULTS The mRNA transcription of CYP3A4 mutants in Sf9 cells were validated by RT-PCR. Testosterone and 7-benzyloxy-4-(trifluoromethyl) coumarin were metabolized by the lysates of Sf9 cells infected by the recombinant viruses. CONCLUSION CYP3A4 mutants CYP3A4.3, CYP3A4.4, CYP3A4.5 and CYP3A4.18 with metabolic activity were successfully expressed by baculovirus-insect cell expression system. The results indicated that recombinant CYP3A4. 5 showed lower activity comparing to the wild type protein towards testosterone, while CYP3A4. 18 with higher activity, and for CYP3A4.3 and CYP3A4.4 showing similar activity to the wild type protein.

8

Cite

Share

Protection of δ-opioid receptor stimulation against injured myocardial cells by hydrogen peroxide

Jiong LI ; Zhongyan WANG ; Min YU

Chinese Journal of Pharmacology and Toxicology.2009;23(6):431-435. doi:10.3867/j.issn.1000-3002.2009.06.003

AIM To study protective effect of [D-Ala~2, D-Leu~5]-enkephalin (DADLE) against hydrogen peroxide (H_2O_2) induced myocardial cell injury and its possible mechanisms. METHODS Myocardial cells were isolated from neonatal rats and cultured for 48 h. Then the cells were randomly assigned into normal control, H_2O_2（200 μmol·L~(-1)）, H_2O_2+DADLE(1 μmol·L~(-1)), H_2O_2+DADLE +naltrindole(10 μmol·L~(-1)) and H_2O_2+DADLE +U0126(10 nmol·L~(-1)) groups and cultured for another 48 h.[~3H]TdR incorporation assay and flow cytometry were used to measure the cell proliferation and apoptosis rate. The lactate dehydrogenase (LDH) activities in culture supernatant measured by using LDH activity kit. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cells were measured with xanthine oxidase method and color reaction of thiobarbituric acid, respectively. The expressions of extracellular signal-regulated kinase (ERK) and phosphorylated-ERK (p-ERK) were observed with Western blot. RESULTS ① Compared with normal control group, the incorporation of [~3H]TdR in myocardial cells of H_2O_2 group was significantly lower, apoptosis rate was higher, LDH activity and MDA content in cells were higher, while SOD activity in cells was lower. In addition, the ratio of IA_( p-ERK) /IA_( ERK) was decreased. ② Compared with H_2O_2 group, the incorporation of ［3H］TdR in H_2O_2+DADLE group was significantly higher, apoptosis rate was lower, LDH activity and MDA content in cells decreased, while SOD activity increased significantly. The ratio of IA_( p-ERK) /IA_( ERK) was increased. ③ δ-Opioid receptor antagonist naltrindole and ERK antagonist U0126 inhibited this effect of DADLE on the above index changes induced by H_2O_2. CONCLUSION The δ-opioid receptor has protective effect against H_2O_2-induced myocardial cell injury, and its possible mechanism may be related to its promotion of antioxide capacity and ERK phosphorylation.

9

Cite

Share

Protective effects of pioglitazone against lipopolysaccharides-induced neurotoxicity in cultured cortical neurons in rats

Haijuan SUI ; Ying JIN ; Yuexing PAN ; Zhijuan ZHANG ; Rui WANG

Chinese Journal of Pharmacology and Toxicology.2009;23(6):423-430. doi:10.3867/j.issn.1000-3002.2009.06.002

AIM To investigate whether pioglitazone can protect cortical neurons from lipopolysaccharides(LPS)-induced neurotoxicity and the mechanisms responsible for this protective effect. METHODS After 7 d cultures，cultured cortical neurons were incubated with LPS 10 mg·L~(-1) for 4-24 h with or without other drugs. In co-incubation experiments, other drugs were added to the neurons 30 min or 1 h prior to incubation with LPS. The cell viability was assessed by MTT assay. The neuronal apoptosis was quantified by scoring the percentage of cells with apoptotic nuclear morphology after Hoechst 33258 staining. The cultured cells were then fixed on the 7th day and immunocytochemically stained with phosphorylated JNK1 antibody. The protein expressions of active caspase 3 and phosphorylated JNK1 were measured by Western blot. Nitric oxide (NO) generation was measured by Griess method. RESULTS The decrease of cell viability and the increase of apoptotic cells in cultured cortical neurons were observed incubated with LPS for 24 h compared with the normal controls. The cell viability of cortical neurons was decreased from (100.0±10.9)% in the normal control group to (72.3±2.1)% in the LPS-treated group and the apoptotic cell percentages were increased from (11.5±4.2)% in the normal control group to (39.5±8.2)% in the LPS group. LPS induced the increases in phospho-JNK1, active caspase 3 expression, and NO generation. Pioglitazone 0.01, 0.1 and 1 μmol·L~(-1), respectively inhibited LPS-induced decrease in cell viability and increase of apoptotic morphology, active caspase 3 expression in cultured neurons. In LPS+pioglitazone 1 μmol·L~(-1) group, cell viability was （97.8±9.7）%, the apoptotic cells percentage was (20.6±5.0)%, NO generation (6.8±1.3)μmol·L~(-1). Furthermore, pioglitazone also inhibited LPS-induced the increase in JNK1 phosphorylation and NO generation. JNK inhibitor SP600125 5 μmol·L~(-1) significantly inhibited LPS-induced neurotoxicity, cell viability was increased from (72.3±2.1)% to (109.8±11.8)%, the apoptotic cells percentage from (39.5±8.2)% decreased to (19.1±4.8)%, NO generation from （21.1±5.0）μmol·L~(-1) decreased to（4.0±1.3）μmol·L~(-1). The PPARγ antagonist GW9662 10 μmol·L~(-1) did not reverse the effects of pioglitazone. In LPS+pioglitazone 1 μmol·L~(-1)+GW9662 10 μmol·L~(-1) group, cell viability was (90.7±6.9)%, the apoptotic cells percentage was (23.4±4.1)%, and NO concentration was (5.8±0.7)μmol·L~(-1). CONCLUSION Pioglitazone protects cortical neurons against LPS insult at least via inhibiting JNK activity and NO generation, but not PPARγ activation.

10

Cite

Share

Effect of tocotrienol rich fraction of palm oil on glucose metabolism in atherosclerotic mice

Fengjuan LI ; Zhanfang KANG ; Zhiwei HUANG

Chinese Journal of Pharmacology and Toxicology.2009;23(6):472-479. doi:10.3867/j.issn.1000-3002.2009.06.009

AIM To investigate the effect of tocotrienol rich fraction of palm oil (TRF) on glucose metabolism in atherosclerotic mice and the possible mechanism. METHODS Apolipoprotein E gene deficient(ApoE~(-/-)) mice were divided into 3 groups as model control, TRF 0.05% and 0.2%(W/W) groups. 10% (W/W) fat and 0.2% (W/W) cholesterol were added into the diets to induce atherosclerosis formation. Oral glucose tolerance test and insulin tolerance test were conducted after mice were treated by TRF for 12 and 14 weeks respectively. Serum cholesterol, triglyceride, free fatty acid, and insulin levels were measured using corresponding kits. The mRNA expression levels for peroxisome proliferator-activated receptor γ(PPARγ), adiponectin and glucose transporter 4 (Glut4) in white adipose tissue (WAT) were determined by using quantitative real-time PCR. Activation of PPARγ by TRF was tested using luciferase reporter assays. RESULTS Compared with the model control group, TRF decreased non-fasting or fasting blood glucose levels and improved insulin sensitivity of ApoE~(-/-) mice. Both TRF groups showed decreased levels of triglyceride and free fatty acid. The mRNA level of adiponectin in WAT was up-regulated by (1.73±0.32) times in TRF 0.2% group compared with the control group. Glut4 mRNA level was increased (1.89±0.24) and (2.01±0.61) times compared with control group in TRF 0.05% group and TRF 0.2% group respectively. The fold inductions of TRF on PPARγ-ligand-binding domain, PPARγ1 and PPARγ2 activities were (2.7±0.2), (6.1±0.65) and (5.3±0.1) times compared with DMSO by using luciferase reporter assay. CONCLUSION TRF can improve glucose metabolism in atherosclerotic mice and this effect may be partly due to modulating the activity of PPARγ.

DISPLAY OPTIONS

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share