Objective To explore the invading mechanism of amebae in lamina porpria and observe the interaction between the cysteine proteinase (CP) of Entamoeba histolytica and laminin. Methods CP was identified by laminin-sepharose affinity chromatography, followed by isolation, purification and inhibitor experiment. The hydrolytic activity was measured by gelatin electrophoresis. Results Purified CP of E.histolytica showed a strong affinity with laminin. The molecular weight of CP is 27 kDa. It can be inhibited by EC-64 and exhibited a protein hydrolytic activity. Conclusion The specific affinity and hydrolytic activity of CP might play an important role in its invasion to the basement membrane of intestinal mucosa.

OBJECTIVE: To study the preventive effect of Breviscapus Injection on the chronic hypoxic myocardium injury in rats and its mechanism. METHODS: Transmission electron microscope and biochemical analysis were used to assay the therapeutic effect of Breviscapus Injection in rat model induced by 4 week's hypoxia. RESULTS: The contents of malondialdehyde (MDA) and Ca(2+) in the homogenate of myocardial tissue of the hypoxic rats were significantly higher than those of the control rats. The activities of superoxide dismutase (SOD), nitric oxide synthase (NOS) in the homogenate of myocardial tissue and the plasmic NO levels of the hypoxic rats were significantly lower than those of the control rats. Breviscapus Injection reduced the contents of MDA and Ca(2+), and increased the levels of SOD, NOS and NO. Ultrastructural examination revealed that the injuries of the ultrastructure of heart in hypoxic rats were improved by treatment with Breviscapus Injection. CONCLUSION: Breviscapus Injection can effectively prevent and treat the hypoxia-induced myocardial damage. One of its mechanisms may relate to its adjusting NO level, anti-damaging of free radicals and inhibiting calcium overload.

Purpose　To study myocardial pathology and its pathogenesis in diabetes. Methods　Myocardial structure of alloxan induced diabetic rats was observed under light microscopy (LM)and transmission electron microscopy(TEM).Activity of superoxide dismutase(SOD),glutathione peroxidase (GSH-Px)，nitric oxide synthase(NOS)and content of malondialdehyde (MDA),nitric oxide(NO) were detected biochemically in myocardial homogenate. Results　Atrophy and degeneration of myocardium and interstitial fibrosis were found under LM and expansion of mitochondria and smooth endoplasmic reticulum, destruction of myofibril and interstitial proliferation of collogen fiber under TEM. Activity of SOD and GSH-Px decreased significantly, while content of NO and MDA and activity of NOS increased significantly in diabetic rats. Conclusion　Atrophy of myocardium, expansion of mitochondria,destruction of myofibril and interstitial fibrosis are the main morphological changes of diabetic cardiomyopathy, and lipid peroxidation and NO may be involved in it.

ObjectiveTo observe the protective effects of extract gingko biloba (EGb) on the myocardium mitochondria of diabetic rats.Methods40 Sprague-Dauley rats were divided randomly into the normal control group, diabetic group and EGb treatment group. The morphologic changes of myocardium mitochondria were studied by electron microscope, and the activities of succinate dehydrogenase (SDH), superoxide dismutase (SOD), nitric oxide synthase (NOS) and content of nitric oxide (NO), malondialdehyde (MDA) in the myocardium mitochondria were assayed by spectophotometer respectively.ResultsThe expansion of mitochondria, shorten of mitochondrial crest were observed under transmission electron microscope in diabetic rats. The activities of SOD and SDH decreased, but that of NOS and the content of NO increased in the diabetic group compared with control group. In EGb treatment group, the morphological change was slight, the activities of SOD and SDH were increased as well as NOS and the content of NO, MDA decreased compared with the diabetic group.ConclusionEGb can protect myocardium mitochondria of experimentally diabetic rats from lesion of free radical and excessive NO, and enhance the activity of SDH, protect myocardium of diabetic rat consequently.

AIM: To study testicular pathological change and its pathogenesis. METHODS:Testicular structure of alloxan induced diabetic rats was observed under light microscopy (LM)and transmission electron microscopy(TEM). Activity of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX),nitric oxide synthase(NOS)and content of malondialdehyde (MDA),nitric oxide(NO) were detected biochemically in testicular homogenate. RESULTS: It is manifestated as atrophy of seminiferous tubule and germinal arrest under LM and expansion of mitochondria and smooth endoplasmic reticulum, cytoplasmic inclusion of sertoli cell under TEM.Activity of SOD, GSH-PX decreased while activity of NOS, content of MDA, NO increased in diabetic rats compared with control one. CONCLUSION: Disturbance of spermatogenesis and damage of sertoli cell are the main morphological change of diabetic testis, lipid peroxidation and NO may be involved in it.

AIM: To investigate the effect of chronic hypoxia-hypercapnia and L-arginine (L-Arg) liposome on L-Arg transport in rats pulmonary artery. METHODS: Forty Sprague-Dawley rats were randomly divided into four groups, normal control group (NC), chronic hypoxia-hypercapnia group (HH), chronic hypoxia- hypercapnia group+L-Arg (HL) and chronic hypoxia-hypercapnia group+L-Arg liposome (HP). Changes in pulmonary artery L-Arg transport and pulmonary arterial microscopy were observed. RESULTS: (1) The mean pulmonary artery pressure (mPAP) and weight ratio of right ventricle to left ventricle and septum (RV/LV+S) in HH group were higher than those in NC group, and in HP group was lower than that in HH group and HL group, but there was no significant difference between HL group and HH group; (2) At 0.005 mmol/L, 0.01mmol/L, 0.02mmol/L, 0.05 mmol/L, 0.1 mmol/L and 0.2mmol/L concentration of L-Arg, the velocity of L-Arg transport in HH group was lower than that in NC group, and in HL group higher than in HH group, and in HP group was much higher than that in HH group and in HL group. (3) Light microscopy showed that vessel well area/total area (WA/TA) and media thickness of pulmonary arterioles (PAMT) were much higher in rats of HH group than those in NC group, WA/TA and PAMT in HP group were obviously improved. CONCLUSION: The above results indicated that there existed a functional disturbance in L-Arg transport of pulmonary artery in rats chronically exposed to hypoxia-hypercapnia, and it was obviously enhanced when liposome was used as L-Arg carrier. Thus, it appears that liposome-L-Arg may have clinical perspective in the treatment of chronic hypoxic pulmonary hypertension.

AIM: To investigate the protective effect of Ginkgo biloba extract (GBE) on diabetic testis and explore its possible mechanism. METHODS: Testicular structure of streptozotocin-induced diabetic rats was observed under light microscopy (LM) and transmission electron microscopy (TEM). Content of malondialdehyde (MDA), NO_2~-/NO_3~- and activity of superoxide dismutase (SOD), nitric oxide synthase (NOS) were determined in testicular homogenate. RESULTS: In diabetic rats, it was manifestated as deformation of seminiferous tubule, atrophy and shedding of germinal epithelium under LM, while expansion of smooth endoplasmic reticulum, formation of fatty vacuoles and decrease of lysosome obviously in the cytoplasm of sertoli cell under TEM, the injury of testicular tissue was improved by GBE. Compared with diabetic rats, activity of SOD increased while activity of tNOS and iNOS, content of MDA and NO_2~-/NO_3~- decreased in GBE-treated rats. CONCLUSION: GBE could effectively prevent the development of diabetic testis and the effect may be partly achieved by resisting lipid peroxidation,restraining the activity of testicular tissue iNOS and reducing the pathological alterations of NO. [

AIM: To investigate the effects of extract of Ginkgo biloba (EGb) on diaphragm from diabetic rats. METHODS: Sprague-Dauley rats were divided into three groups: normal control, diabetic group and EGb treatment group. The morphologic changes of diaphragm tissues were studied by light and electron microscopy, the activities of succinate dehydrogenase (SDH), superoxide dismutase (SOD), nitric oxide synthase (NOS) and contents of malondialdehyde (MDA), nitric oxide (NO_2~-/NO_3~-) in the diaphragm mitochondria were assayed by spectophotometer, respectively. RESULTS: The activities of SOD, SDH decreased in diabetic diaphragm mitochondria, but the activitiy of NOS, the contents of NO_2~-/NO_3~-, MDA increased compared with control group. The activities of SOD, SDH were increased as well as NOS were decreased and the contents of NO_2~-/NO_3~-, MDA decreased in EGb treatment group compared with the diabetic group. CONCLUSION: EGb may protects the diaphragm mitochondria of diabetic rats by enhancing the function of respiratory chain, anti-oxidation and decreasing NO level. [

AIM: To study the protective effects of the extract of Ginkgo biloba (EGB) on brain tissues in experimental diabetic rats and explore its possible mechanisms. METHODS: Thirty male Sprague-Dauley rats were divided into three groups: normal control group, diabetic group and EGB-treated group. Strepozotocin were injected intraperitoneally on the later two groups to induce diabetes, EGB-treated group was injected intraperitoneally with EGB, and the others were treated with normal saline at the same volume. After five weeks, the content of endothelin (ET), malondial dehyde (MDA), NO2~-/NO 3~-, and the activity of superoxide dismutase (SOD), nitric oxide synthase (NOS) were determined in brain homogenate, and the level of blood glucose, insulin and ET were measured respectively. In addition, the morphologic changes of the brain tissue were studied by light microscopy and electron microscopy, respectively. RESULTS: In diabetic group, there were degeneration of neuron, brain edema, softened focus and demyelination in the white matter of brain by light microcopy. There were expansion of mitochondria of neuron and gliocyte, the shortened of crista, demyelination of neurofiber and injury of blood-brain-barrier by the electron microscopy. After treated with EGB, the pathological changes decreased in brain under light microcopy and electron microcopy. Compared with diabetic rats, the activity of SOD and the level of serum insulin increased, while the level of blood ET, the activity of NOS, the content of ET, MDA, NO2~-/NO3~- decreased in EGB-treated rats (P

AIM:To study testicular pathological change and its pathogenesis. METHODS:Testicular structure of alloxan induced diabetic rats was observed under light microscopy (LM)and transmission electron microscopy(TEM). Activity of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX)，nitric oxide synthase(NOS)and content of malondialdehyde (MDA),nitric oxide(NO) were detected biochemically in testicular homogenate. RESULTS:It is manifestated as atrophy of seminiferous tubule and germinal arrest under LM and expansion of mitochondria and smooth endoplasmic reticulum, cytoplasmic inclusion of sertoli cell under TEM.Activity of SOD, GSH-PX decreased while activity of NOS, content of MDA, NO increased in diabetic rats compared with control one. CONCLUSION:Disturbance of spermatogenesis and damage of sertoli cell are the main morphological change of diabetic testis, lipid peroxidation and NO may be involved in it.