Effects of Cimetidine on L ow Dose Rate Irradiation-induced Liver Cell Apoptosis in Beagle Dogs and Its Mechanism / 中国药房

OBJECTIVE： To study the effects of cimetidine on low dose rate irradiation-induced liver cell apoptosis in Beagle dogs. METHODS： Healthy male Beagle dogs were randomly divided into normal control group， model control group， positive drug group （lentinan， 21.33 mg/kg） and cimetidine low-dose， medium-dose and high-dose groups （5.33， 10.67， 21.33 mg/kg）， with 4 Beagle dogs each. Except for normal control group， other groups were given 60Co-γ accumulative irradiation （dosage rate： 0.040 8 mGy/min） for 23 d； the medication groups were given relevant medicine orally before irradiation， once a day. Twenty-four hours after stopping irradiation， TUNEL method was used to detect the apoptosis of liver cells in Beagle dogs. The percentage of apoptotic cells was calculated. The expression level of apoptosis-related proteins （Bax， Bcl-2， Caspase-3， p53） in liver tissue was detected by immunohistochemistry. RESULTS： Compared with normal control group， apoptotic cells and Bax， Caspase-3， p53 positive cells were increased significantly in liver tissue of Beagle dogs in model control group； the percentage of apoptotic cells， protein expression levels of Bax， Caspase-3 and p53 were increased significantly； Bcl-2 positive cells were decreased significantly， and its protein expression level was decreased significantly （P＜0.05 or P＜0.01）. Compared with model control group， above positive cells of liver tissue in Beagle dogs were changed to different extents in medication groups； the percentage of apoptotic cells and protein expression levels of p53 in medication groups， protein expression levels of Bax in positive drug group， cimetidine low-dose and high-dose groups as well as protein expression levels of Caspase-3 in cimetidine groups were decreased significantly； protein expression levels of Bcl-2 were increased significantly in cimetidine groups. The percentage of apoptotic cells in cimetidine medium-dose and high-dose groups as well as protein expression levels of Caspase-3 in cimetidine groups were all lower than positive control group. Protein expression level of p53 in cimetidine low-dose group was significantly higher than positive drug group （P＜0.05 or P＜0.01）. CONCLUSIONS： Cimetidine can inhibit the low dose rate irradiation-induced apoptosis of liver cells in Beagle dogs， and certainly protect liver cells against irradiation. The mechanism of it may be associated with up-regulating the protein expression of Bcl-2 and down-regulating the protein expression of Bax， Caspase-3 and p53 in liver cells.

Protective effects of cimetidine against oxidative stress induced by low-dose irradiation / 解放军医学杂志

Objects To study the protective effects of cimetidine against oxidative stress in rats induced by cumulative low-dose irradiation.Methods Sixty SD rats were randomly divided into 6 groups (10 each):normal control group,model control group,lentinan group [89mg/(kg.d)] and 3 dose groups of cimetidine.After oral administration,all the rats were exposed to γ-ray irradiation 8 hours/day for 12 days,and sacrificed on the 13th day.The activities of superoxide dismutase (SOD),glutathione peroxidase (GPx),catalase (CAT) and the content of malondialdehyde (MDA) in serum,liver,thymus and spleen were determined.By using the superoxide anion radical system,hydroxyl radical system,H2O2 radical system,oxidation system of linoleic acid induced by alkane radical system and diphenyl picryl hydrazinyl radical (DPPH) radical system,the antioxidation activities of cimetidine were detected.Results The activities of SOD in liver and thymus decreased significantly,the GPx activity in serum,liver and spleen decreased significantly and MDA level in serum,liver and spleen increased significantly after 0.3Gy cumulative ionizing radiation.Cimetidine enhanced the activities of antioxidant enzymes in serum and organs,and reduced the MDA level.In a certain concentration range,cimetidine had different scavenging effects onto these radical systems,and showed good performance in hydroxyl radical.Conclusion Cimetidine can effectively ameliorate the oxidative stress from low-dose cumulative irradiation by scavenging free radicals,increase the activity of antioxidant enzymes and reduce the content of lipid peroxidation products,thus presents a potential radio protective effect.

Radioprotective effect of cimitidine on acutely irradiated mice survival and hematopoietic system / 解放军医学杂志

Objective To investigate the radioprotective effect of cimetidine on survival rate and hematopoietic system in acutely irradiated mice.Methods The total body irradiation doses were 6.0Gy and 8.0Gy respectively at 1.01Gy/min rate. Sixty healthy male C57BL/6 mice were randomly divided into control group, model group, positive-drug (523) group and cimetidine groups (33.3mg/kg, 100mg/kg and 300mg/kg). Each group had ten mice. The mice were given intragastric administration of cimetidine for 6d before the irradiation in cimetidine groups, and 523 was administered before irradiation once a day for one day in 523 group, and at 5h after irradiation, was given again. The 30d survival rate after 8.0Gy irradiation was recorded. The peripheral blood cells, bone marrow DNA content and frequency of micronucleated polychromatic erythrocytes (fMNPCE) were determined 30d after 6.0Gy irradiation.Results After 8.0Gy irradiation, all the mice died on 21th day in model control group. The survival rates in cimetidine groups were 50%, 20% and 30%, respectively. After 6.0Gy irradiation on 30th day, compared with control group, the peripheral white blood cells (WBC) and bone marrow DNA content were decreased significantly (P<0.01,P<0.05) in model group, and fMNPCE was increased significantly (P<0.05). Compared with model group, WBC was significantly increased in 300mg/kg cimetidine group (P<0.01). In cimetidine groups, the bone marrow DNA content was increased significantly after irradiation (P<0.01 orP<0.05), and the fMNPCE was decreased significantly (P<0.01 orP<0.05) and tended towards normal.Conclusion Cimetidine could improve 30d survival rate of acutely irradiated mice and has good protective effect on hematopoietic system.

Preliminary Study on Quality Standard for Sipunculus Nudus Polysaccharide / 中国药师

Objective:To establish the quality standard for Sipunculus nudus polysaccharide. Methods:The water content, igni-tion residues and heavy metals in Sipunculus nudus polysaccharide were determined. Authrone-sulfuric acid colorimetry was used to de-termine the polysaccharide content. Results: The water content in the polysaccharide should not exceed 5. 0%, ignition residues should not exceed 1. 0%, and the content of heavy metals should not exceed 20 ppm. The polysaccharide content should exceed 80%( glucose) . Conclusion:The method is accurate and simple, and can be effectively used in the quality control of polysaccharide in Sipunculus nudus Linnaeu.

Preparation Technology of Buccal Tablets Containing Old Tea Leaf Extract / 中国药师

Objective:To prepare old tea buccal tablets using wet granulation method and optimize the preparation technology. Methods:The amount of each adjuvant was studied by single factor experiments, and the formula of the buccal tablets was optimized by the orthogonal experiments using taste and disintegration time as indices. Results:The optimal formula was composed of old tea ex-tract 30 g,mannitol 60g,PEG6000 20 g,aspartame 10 g,citric acid 10 g and menthol crystal 1 g. All the tested indices including ap-pearance, hardness and disintegration time met the requirements described in Chinese pharmacopeia. Conclusion: The preparation technology is reasonable and feasible for the industrial production.

The combined biological effects of low dose radiation, carbon monoxide, benzene and noise on rats / 中华放射医学与防护杂志

Objective To investigate the combined biological effects of low dose radiation,carbon monoxide,benzene and noise on rats.Methods Sixteen male SD rats were randomly divided into experiment group and control group.The experiment group was exposed to carbon monoxide,benzene,low dose radiation and noise daily,the control group was in common environment.Peripheral blood,organ index,and marrow DNA content were detected.Two-dimensional electrophoresis (2-DE) was performed on serum protein analysis.Differential expressed proteins were identified by a matrix assisted laser desorption/ionization time of flight mass spectrometry (MAIDI-TOF-MS).Results Compared to control group,the liver index,spleen index,thymus index,leukocytes,platelets count,and marrow DNA content of the experiment group were decreased significantly (t =2.732,4.141,3.053,2.211,2.668,11.592,P ＜0.05).12 altered proteins were detected and through identification,3 proteins were definite in terms of serum amyloid A-4 protein (SAA4),trichoplein keratin filament-binding protein (TCHP) and tubulin alpha-4A chain (TUBA4A).Conclusions The hematopoietic system and immune system of rats are damaged significantly with the changes of several serum protein expressions by the combined exposure of low dose radiation,carbon monoxide,benzene and noise.This study may provide new information for the mechanism of the combination effects.

Immunogenicity of a multiple epitope antigen gene of hepatitis C virus in mice and rabbits / 细胞与分子免疫学杂志

Aim To explore the possibility of the multiple epitope DNA vaccines of hepatitis C virus (HCV). Methods A synthetic multiple epitope antigen gene PCX of HCV was cloned into vector pREP9(RSV promoter) and pcDNA3 (CMV promoter) to construct eukaryotic expression vectors pREP9/PCX and pcDNA3/PCX, then they were used to immunize mice and rabbits, the titer of specific humoral and cellular responses were detected and their safety were observed. Results In mice, specific anti-GZ-PCX antibody(IgG) was lower than 1∶ 1 000 and did not persist well. In rabbits, the highest titer of anti-GZ-PCX IgG reached at 1∶ 3 200 and remained for about one month. Delayed type hypersensitivity reactions (DTH)and proliferation response of peripheral lymphocytes were induced by GZ-PCX antigen. Body weights of immunized mice were normal and no obvious toxic reaction was observed. Conclusion The multiple epitope antigen gene of HCV could induce specific immune responses without obvious toxicity and it might be able to serve as an effective HCV vaccine candidate.

The relationship between Fas expression and thymocytes spontaneous apoptosis in vitro / 细胞与分子免疫学杂志

Aim To study the relationship between the expressions of Fas,Fas-L and the spontaneous apoptosis of thymocytes in vitro. Methods The expressions of Fas,Fas-L and the apoptotic rate of thymocytes were assayed by flow cytometry. Results The apoptosis and the Fas expression of thymocytes of different culture times in vitro were increased time-dependently in vitro. The Fas-L expression of thymocytes cultured for 24 h was also significant increase. There was significant corelation between the increase of Fas expression and the increase of apoptosis of thymocytes in vitro. Conclusion Fas is an important molecule which mediates spontaneous apoptosis of thymocytes cultured in vitro.

Protective effect of Sipunculus nudus preparation on mouse irradiated by ~(60)Co / 中国海洋药物

Objective To evaluate the protective effects of Sipunculus nudus preparation(SNP) on mice irradiated by 60Co.Methods The mice were divided into control group,model group and 0.5,1.0,and 2.0g?kg-1?d-1 SNP groups.SNP was administrated by intra-gastric infusion with the volume of 0.4mL per 20g.In the fifteenth day,the model group and the treated groups were irradiated by ?-ray of 60Co(0.83Gy/h) with the dose of 5 Gy.Peripheral blood WBC,RBC,PLT,the spleen(SI) and thymus index(TI),the BMNC,SOD and MDA in serum,testicle index,germ cells were detected.Results Comparing with the model group,TI,SI and peripheral blood WBC,RBC and BMNCs were higher.The activities of SOD in serum were increased,while MDA decreased.Testicle index and germ cells were increased,and germ abnomality rate was decreased in SNP groups.Conclusion SNP has protective effects on mice irradiatied by 60Co.

Toxicological study on Jiutong Capsule / 中成药

AIM:To estimate the toxicological characterization of Jiutong Capsule(Radix Puerariae lobatae,Fructus seu Semen Hoveniae,etc.).METHODS:The acute toxicity test,micronucleus test of bone marrow cell,sperm shape abnormality test in mice,the Ames test,and 30 days feeding test in rat were performed.RESULTS:(1) The acute toxicity test showed that LD_ 50 of Jiutong Capsule was more than 10.0 g/kg.(2) The result of Ames test,micronucleus test of bone marrow cell,and sperm shape abnormality test were negative.(3) The 30 days feeding test showed that Jiutong Capsule had no cumulate toxicity in mice.CONCLUSION:The results show that Jiutong Capsule does not have toxicity,and it can't cause mutation and heredity toxicity.

Preparation of Cartilage Antitumor Component and Its Effects on Human Tumor Cell Lines / 第二军医大学学报

Cartilage antuumor component (CATC) was isolated from a 1 mol/L guanidine hydrochloride extract of bovine cartilage by acetone fractioned precipitation and superfiltration. Using human skin fibroblasts as a normal control, it was demonstrated that CATC inhibited the DNA synthesis of Hela, QGY7703 tumor cell lines and bovine artery endothelial cells, but accelerated the normal cells, when the concentration was below 1250 ?g/ml. At the concentration of 5 000 ?g/ml, CATC inhibited the two cell lines. With human tumor stem cell assay, CATC inhibited the stem cell growth of Hela and QGY7703 cell lines. These suggest that CATC has the effects of inhibiting angiogenesis and tumor cells.