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Objective To observe the lecithin's effect on membrane of African green monkey kidney cells (Vero) exposed to sodium arsenite(NaAsO2). Methods Vero cells cultured in vitro were divided into 4 groups:control group (saline), model group (2.20 mg/L NaAsO2), high eoncentration of lecithin and arsenic group (53.33mg/L lecithin + 2.20 mg/L NaAsO2), low eoncentration of lecithin and arsenic group( 13.32 mg/L lecithin + 2.20 mg/L NaAsO2), 6 bottles of cells in each group, medium was changed every 2 days, cultured for 120 h. Na+ ,K+-ATPase activities of membrane were measured by spectrophotometry, and membrane phospholipids composition including phosphatidylserine (PS), phosphatidylethano-lamine (PE), phosphatidylcholine (PC) and sphingmyelin (SM) were measured by high performance liquid chromatography (HPLC). Results The Na~, K+-ATPase activities of membrane of control group, model group, high concentration of lecithin and arsenic group, low concentration of lecithin and arsenic group were (0.962 ± 0.081) × 106, (0.544 ± 0.037) × 106, (0.647 ± 0.043) x 106, (0.550±Compared with control group, the Na+ ,K+-ATPase activities of other 3 groups were significantly reduced (all P 0.05). Compared with control group[(0.087 ± 0.003), (0.127 ± 0.053), (0.588 ± 0.105),(0.071 ± 0.029)g/L], PS, PE, PC, SM levels in model group[(0.051 ± 0.018), (0.073 + 0.030), (0.240 ±0.038), (0.047 ± 0.121 )g/L] were significantly lower(all P 0.05), but SM[(0.057 ± 0.004)g/L] significantly decreased(P 0.05]. Compared with model group,the levels of PS, PE, PC, SM in high concentration of lecithin and arsenic group were significantly higher(all P 0.05), and PC was significantly higher(P < 0.05). Conclusions High concentration lecithin has certain protective effect on Vero cell membrane exposured to sodium arsenite.
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Objective: To study the effect of low concentration of ouabain MUM on intracellular calcium concentration ([Ca2+]i) in guinea pig ventricular myocytes and to understand whether low concentration of OUA can increase [Ca2+]i through Na+, K+-ATPase channel. Methods: The guinea pig ventricular myocytes were obtained by enzymatic digestion and the [Ca2+]i fluorescent density of individual myocytes was observed under confocal laser scanning microscope. The isolated ventricular myocytes were then incubated with different concentrations of ouabain(10-9, 10-8, 10-7, 10-6 mol · L-1). The sediment was subjected to Western blot analysis to assess the phosphorylation of Src by OUA. Results: In normal Tyrode' s solution and Ca2+-free Tyrode's solution, OUA (1 × 10-9 -1 × 10-6) mol · L-1 elevated [Ca2+]i in a concentration-dependent manner, with the elevation in normal Tyrode's solution more obvious (P < 0.05). Genistein (GST) (1, 10, 50, and 100 μmol - L-1) abolished the OUA-induced increases of [Ca2+]i in a concentration-dependent manner. There were two tyrosine-phosphorylated bands, with the molecular weights being 120 000 and 70 000. Compared with control group, the densities of the 2 bands in all OUA groups were significantly higher (P<0.05) and GST could obviously inhibit the elevating effect of OUA. Conclusion: Low concentration of OUA may promote opening of Ca2+ channel and release of intracellular Ca2+, and subsequently elevate intracellular free calcuim through phosphorylation of tyrosine and activition of OUA/Na+, k+-ATPase/Src signal transduction pathway.
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The antioxidative capability and Na+-K+-ATPase α1-subunit mRNA expression in myocardium of hypothyroid rats induced by low-iodine diet were observed. The results showed that the antioxidative capability of myocardium decreased, resulting in lipid peroxidative damage, atrophy of myocardial cells and chondrification of tunica intima, along with decreased expression of sodium pump α1 subunit mRNA in hypothyroid rats.
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Objective To investigate the mechanism of intracellular calcium and other ions disturbance by measuring the activity of Ca 2+ adenosine triphosphatase (Ca 2+ ATPase) and Na + K + adenosine triphosphatase (Na + K + ATPase) Methods Model of fetal rats ischemia and reperfusion was established The duration of ischemia was 15,30,45 and 60mins respectively;after ischemia for 15 mins, reperfusion for 1,4,8,15 and 24 hours There were 7 11 fetal rats sacrificed at different time points respectively, 12 rats in sham for control The mitochondria and endoplasmic reticulium (microsomia) were estracted and the activity of the enzyme was measured Results In the ischemia group: with the development of ischemia, the activity of Ca 2+ ATPase in mitochondria decreased gradually ( P
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AIM: To observe the effect of endoxin antagonist,anti-digoxin antiserum,on endoxin level,ATPase activities,intramitochondrial total calcium concentration and gene expression of sodium pump isoforms in myocardium of rats with myocardial ischemia reperfusion(MIR).METHODS: Fifty-six male Sprauge Dawley rats were randomly divided into 7 groups.Sham operation group: silk suture threading the left anterior descending coronary artery without ligature;MIR group: left anterior descending coronary artery was subjected to 30 min ligation followed by 45 min reperfusion;normal saline group: MIR model was given 5 mL/kg normal saline;verapamil group: MIR model was given 5 mg/kg verapamil;low dose antidigoxin antiserum group: MIR model was given 8.6 mg/kg antidigoxin antiserum;middle dose antidigoxin antiserum group: MIR model was given 17.3 mg/kg antidigoxin antiserum;high dose antidigoxin antiserum group: MIR model was given 34.5 mg/kg antidigoxin antiserum.All drugs were injected into vessel via femoral vein within 5 min before reperfusion,respectively.After reperfusion,left ventricle myocardium samples were processed immediately in order to measure the activity of Na+-K+-ATPase and Ca2+-Mg2+-ATPase,endoxin level,intramitochondrial total calcium concentration and the experssion of ?1,?2,?3 and ?1 isoforms of sodium pump on mRNA and protein levels by RT-PCR and Western blotting and immunohistochemical assay,respectively.RESULTS: After MIR,the level of endoxin in myocardium was obviously increased.The activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in myocardial membrane were significantly decreased while intramitochondrial total calcium concentration increased.The gene expression of the ?1,?2,?3 and ?1 isoforms of sodium pump at both mRNA and protein levels were reduced markedly.Only the effect of verapamil on reducing intramitochondrial total calcium concentration was observed.Antidigoxin antiserum significantly reduced the level of endoxin in myocardium,restored the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase,reduced intramitochondrial total calcium concentration,and up-regulated the expression of ?1,?2,?3 and ?1 isoforms of sodium pump at both mRNA and protein levels.CONCLUSION: MIR results in increase of endoxin secretion.The latter depresses the activity of Na+-K+-ATPase by down-regulating the gene expression of ?1,?2,?3 and ?1 isoforms of sodium pump in myocardial membrane,and also induces intramitochondrial calcium overload,thereby mediates MIR injury.
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AIM: To study whether the excitatory amino acids (EAAs)-triggered excitotoxicity contribute to the evolution of hyperbilirubinemia-associated brain injury. METHODS: Newborn rabbits with hyperbilirubinemia were decapitated and then, Na~+-K~+-ATPase activities, neurotransmitters and non-neurotransmitters concentration in brains were determined. RESULTS: It was found that the activities of Na~+-K~+-ATPase both in brains and cytomembrane and the amounts of glutamate (P
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AIM: Changes of endoxin level, ATPase activities, intramitochondrial Ca2+ concentration, and gene expression of Na+-K+-ATPase isoforms in myocardium of rats with MIR and effect of verapamil were observed, in order to investigate mechanism of endoxin mediating intracellular calcium overload of myocytes. METHODS: Twenty four male Sprauge Dawley rats were randomized into 3 groups. Sham operation group: silk suture was threaded the left anterior descending coronary artery without ligature; MIR group (MIR): left anterior descending coronary artery was subjected to 30 min ligation followed by 45 min reperfusion; verapamil group: MIR model was given 5 mg/kg verapamil. Verapamil was injected via femoral vein 5 min before reperfusion. Left ventricle myocardium samples were processed immediately after reperfusion in order to measure the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase, endoxin level, and intramitochondrial Ca2+ concentration. The levels of ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase were measured by immunohistochemical assay. RESULTS: After MIR, the level of endoxin in myocardium was substantially increased; the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in myocardial membrane were significantly decreased while the concentration of intramitochondrial Ca2+ was increased; the levels of the ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase were reduced markedly. Verapamil had only effect on reducing the concentration of intramitochondrial Ca2+. CONCLUSION: MIR increases endoxin secretion. The latter may depress the activity of Na+-K+-ATPase by changing the gene expression of ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase in myocardial membrane, inducing intramitochondrial Ca2+ overload.
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Objective To explore the effect of isoflurane on Na-K-ATPase activity in cultured primary alveolar type Ⅱ(ATⅡ) cells with or without being injured by H 2O 2.Methods ATⅡcells were isolated from adult rat lungs and incubated for 24h and divided into six groups. Group 1 served as control and received no treatment. Group 2 and 3 ATⅡ cells were exposed to 0.28 or 2.8mmol/L isoflurane. In group 4 cells were exposed to 75?mol/L H 2O 2. In group 5 and 6 cells were exposed to both 75?mol/L H 2O 2 + 0.28 or 2.8mmol/L isoflurane. Each group was incubated for another 2h after the addition of isoflurane and /or H 2O 2. The Na-K-ATPase activity of ATⅡcells ,the LDH activity and the MDA concentration of fluid culture medium were measured by biochemical methods.Results Isoflurane markedly decreased Na-K-ATPase activity in normal ATⅡ cells, but aggravated the decrease in Na-K-ATPase activity induced by H 2O 2. Isoflurane had no effect on LHD activity and MDA concentration of fluid culture medium of normal ATⅡ cells ,but significantly increased LHD activity and the MDA concentration of of fluid culture medium of ATⅡ cells injured by H 2O 2.Conclusions Isoflurane can inhibit Na-K-ATPase activity of ATⅡ cells in vitro, and aggravate the damage of ATⅡ cells caused by oxidants.
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Objective To investigate the effect of gastric mucosal blood flow and Na + -K + -ATPase activity on gastric transmucosal potential difference during severe intraperitoneal infection in rats. Methods A rat model of intraperitoneal infection was established by cecal ligation and puncture(CLP). Laser Doppler blood flowmeter was used to examine the gastric mucosal blood flow and electric-physiological recorder was applied for measuring gastric mucosal potential difference. Assay of Na + -K + -ATPase activity in gastric mucosal tissue was conducted by biochemistry method. Results Gastric mucosal blood flow(GMBF,mV) in infected group was significantly lower than in control group(43.7?2.8 vs. 57.9?2.7,P
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AIM:To explore the roles of brain-stem auditory evoked potential(BAEP) in early monitoring the hearing loss and brain damages in hyperbilirubinemia and nitric oxide(NO) in the pathogenesis of bilirubin-induced hearing loss and brain damages.METHODS:Different doses of bilirubin solution(30 mg/kg,60 mg/kg,90 mg/kg,120 mg/kg and 150 mg/kg) were injected into the abdominal cavity of 15-day old SD rats to make the animal model of hyperbilirubinemia.The serum concentrations of bilirubin were detected by a micro-gauge.The bilirubin concentrations in the brain tissues were examined via a diazo method.The Na+-K+ATPase activities in the brain tissues were analyzed by rooting phosphorus.The NO contents in the brain tissues were assayed via the method of nitrate reductase.BAEP were recorded with an evoked potential recorder.RESULTS:After making the ejection,parts of the rats in the high dosage groups(120 mg/kg and 150 mg/kg) showed the abnormal neuro-behaviors.After 6 hours of the ejection,the bilirubin concentrations in serum and in brain tissues,and NO contents in the brain tissues were increased significantly.The Na+-K+ATPase activities in the brain tissues were decreased obviously,and the PL and IPL of BAEP were prolonged significantly in all the experimental rats except the ones in low dosage group(30 mg/kg).The changes of them were closely related to the dose of injected bilirubin.CONCLUSION:The PL and IPL of BAEP are the objective and sensitive indexes for early monitoring the hearing loss and brain damages in hyperbilirubinemia.NO may plays a certain role in the pathogenesis of bilirubin induced hearing loss and brain damages.
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AIM: To study the effect of ?-amyloid protein (?-AP) on the fluidity of mitochondrial membrance in hippocampus of the aging model of rats.METHODS: Based upon the model of aging rats induced by D-galactose (D-gal) and hippocampal microinfusion of ?-AP, the behaviors of rats were observed. Using DPH as fluorescent probe, the viscous cofficient (?) of mitochondrial membrane was determined, and Na +-K +ATPase activity was measured.RESULTS: In the D-gal+?-AP group rats, Na +-K +ATPase activity was lower than D-gal and ?-AP groups ( P