Animals ; Calcium ; metabolism ; Cell Hypoxia ; Cells, Cultured ; Hippocampus ; cytology ; Neurons ; drug effects ; metabolism ; Rats ; Rats, Wistar ; omega-Conotoxins ; pharmacology

Animals ; Animals, Newborn ; Cell Hypoxia ; Cell Lineage ; Cell Proliferation ; Cells, Cultured ; Oligodendroglia ; cytology ; Rats ; Rats, Sprague-Dawley

Objective To establish a method for culturing neonatal mice cardiomyocytes, and construct an in vitro model of cardiomyocytes for assessing the cardiac toxicity of chemicals. Methods Hearts of neonatal mice of 1 day old were digested with enzyme mixture of trypsin/collagenase type Ⅱ/dispase and the cell suspensions were pre-plated to flask for a short time and then seeded on coated dishes. The cultured cells were treated with 5-fiuorine-deoxy-uridine(15 μg/ml)and uridine(35 μg/ml)to enrich cardiomyocytes that were identified according to the morphology and immunocytochemistry of α-actin antigen. Cardiac myocytes were incubated with 0-64 μg/ml of a fusarium mycotoxin butenolide(BUT) for 12 h. Cell viability was then evaluated by MTT assay. Microscopic observation showed that BUT induced significant morphological changes including cellular swelling, vacuolation and breakage of muscle fibers. Results It was found that 96% of the cultured cells were cardiomyocytes and the myocytes kept beating after 90 days of culture. Concentration-dependent decreases in cell viability following exposure of cardiac myocytes to BUT were observed. Conclusion The results indicated that relatively pure primary culture of neonatal mice cardiomyocytes is successfully established. BUT possesses the potential to induce myocardial toxicity.

Objective To investigate the effect of extracorporeal shock wave therapy (ESWT) on early and mid-term knee osteoarthritis (KOA). Methods 70 patients were randomly assigned to ESWT group (n=34) or control group (n=36). The ESWT group was given shock wave on unilateral knee, while the control group accepted shock wave with the energy density of 0. They were evaluated with Visual Analog Scale (VAS) on movement, Lequesne Index and Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index before and 12 weeks after the intervention. Results The scores of VAS, Lequesne Index and WOMAC Osteoarthritis Index improved more in the ESWT group than in the control group after intervention (P<0.01). Conclusion ESWT is effective on KOA as a non-surgical treatment.

Hypoxic preconditioning with different simulated altitudes (3?000 m and 5?000 m) was performed on Wistar rats and the evoked population spikes were recorded from the hippocampal slices of these rats. The results showed that the appearance of hypoxic injury potential (HIP) and the disappearance of presynaptic volley (PV) were significantly delayed in response to acute lethal hypoxia. HIP and PV delay became more apparent when the hypoxic preconditioning altitude was increased from 3?000 m to 5?000 m. After reoxygenation, the recovery rate of PV in hypoxic preconditioning groups at 3?000 m and 5?000 m was apparently higher than that of control. The above results suggest that hypoxic preconditioning of animals in vivo increases hypoxic tolerance of hippocampal neurons.

The effect of CoCl(2) pretreatment on glucose transport activity of cultured newborn rat hippocampal neurons and its role in neuronal hypoxic tolerance were observed. The results showed that the 2-deoxy-D-[1-(3)H ]glucose uptake rate and the mRNA expressions of glucose transporters (GLUT1 and GLUT3) in the hippocampal neurons were significantly increased after a 24-hour pretreatment with CoCl(2). The cell injury induced by 6-hour or 8-hour hypoxic exposure was also greatly reduced by CoCl(2) pretreatment. The protective effect of CoCl(2) on the neurons was largely abolished by cytochalasin B, a specific inhibitor of glucose transporters. The results suggest that CoCl(2) can increase mRNA expressions of GLUT1 and GLUT3 and glucose transporter activity of the neurons, which may be an important mechanism for the increased tolerance of the neurons to hypoxia.
Animals ; Animals, Newborn ; Cell Hypoxia ; Cell Survival ; drug effects ; Cells, Cultured ; Cobalt ; pharmacology ; Glucose Transporter Type 1 ; metabolism ; Glucose Transporter Type 3 ; metabolism ; Hippocampus ; cytology ; Hypoxia ; metabolism ; Neurons ; drug effects ; metabolism ; Organometallic Compounds ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar

AIMTo investigate the effects of anoxia/reoxygenation on Fos and Jun expression and apoptosis in cultured rat hippocampal neurons.

METHODSThe hippocampal neurons cultured for 12 d were exposed to anoxia environment (90% N2 + 10% CO2) for 4 h and then reoxygenated for 24 h and 72 h. The neurons were immunocytochemically stained using the antiserum against Fos and Jun, and the apoptosis were detected by using the terminal deoxynucleotidyl transferase mediated biotinylated deoxyuridine triphosphate nickel end labeling (TUNEL) method and flow cytometric analysis.

RESULTSThe percentage of Fos and Jun positive neurons and apoptosis neurons in cultured hippocampal neurons after anoxia/reoxygenation increased than those in control.

CONCLUSIONThe occurrence of neurons apoptosis is related to the increase in Fos and Jun expression in cultured hippocampal neurons after anoxia/reoxygenation.

Animals ; Apoptosis ; Cell Hypoxia ; Cells, Cultured ; Genes, fos ; Genes, jun ; Hippocampus ; metabolism ; Neurons ; metabolism ; Oxygen ; metabolism ; Rats ; Rats, Wistar

AIMTo investigate the relationship between enhanced anoxic tolerance induced by hypoxic preconditioning and Na+, K+ currents.

METHODSAfter hypoxic preconditioning and acute anoxia the I(Na), I(K) were measured in cultured hypothalamic cells by patch-clamp whole cell recording technique.

RESULTSThe amplification of Na+ currents did not been significantly changed, but the amplification of K+ currents was in hypoxic preconditioning neurons; acute anoxia lead to the inhibition of Na+, K+ currents in the two groups, while Na+, K+ currents in non-preconditioned control group were inhibited severity than hypoxic preconditioning group.

CONCLUSIONIt is presumed enhanced anoxia tolerance induced by hypoxic preconditioning may be related to the opening of K+ channels.

Animals ; Cell Hypoxia ; Cells, Cultured ; Hypothalamus ; cytology ; physiopathology ; Neurons ; physiology ; Oxygen ; physiology ; Patch-Clamp Techniques ; Potassium ; physiology ; Rats ; Rats, Wistar ; Sodium ; physiology

AIMTo study the effects of hypoxic preconditioning on anoxic tolerance and Jun expression in cultured rat hippocampal neurons after anoxia/reoxygenation.

METHODS12 day cultured hippocampal neurons in control and hypoxic preconditioning group were exposed to anoxic environment (0.90L/L N2 + 0.10 L/L CO2) for 4 h, and then reoxygenated for either 24 h or 72 h. The neurons were immunocytochemically stained using the antiserum against Jun. The number of survival neurons and the percentage of Jun expressing neurons were investigated.

RESULTSThe percentage of Jun expressing neurons induced by anoxia in hypoxic-preconditioning group was significantly less than that in control group. The number of survival neurons was more in the hypoxic-preconditioning group than that in control group after anoxic reoxygenation.

CONCLUSIONHypoxic-preconditioning can induce the development of anoxic-tolerance in cultured hippocampal neurons. The decrease in Jun expressing neurons in hippocampus may be an adaptive reaction to acute anoxia.

Animals ; Animals, Newborn ; Cell Hypoxia ; Cells, Cultured ; Genes, jun ; Hippocampus ; metabolism ; Neurons ; metabolism ; Oxygen ; metabolism ; Rats ; Rats, Wistar

AIMTo study the protective effect of Quinacrine(QA) on rat striatum neurons from the injury caused by heat environment treatment, to probe the relationship between cell membrane injury and cellular injury protection, and to seek the possibility of QA as a preventive agent to heat injury.

METHODSPrimary cultured striatum neurons from newborn rats were pretreated with QA at different concentration for 1 h, and then heat-treated at 43 degrees C for another 1 h. Cell necrosis was detected by Trypan blue staining, and apoptosis was evaluated through Activated Caspase-3 dye and TdT dye.

RESULTSHeat treatment effected the survival of striatum neurons and resulted in great number of cell death, which was mainly mediated by cell necrosis process. It was shown that treatment of QA itself had little effect on the survival of striatum neurons, while QA pretreatment decreased cellular necrosis caused by following heat treatment.

CONCLUSIONQA protects striatum neurons from heat environment injury at about 20 pmol/L, and the protection may mediated by reduction of necrosis.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Death ; drug effects ; Cells, Cultured ; Corpus Striatum ; cytology ; Heat-Shock Response ; Neurons ; drug effects ; Quinacrine ; pharmacology ; Rats ; Rats, Wistar