To explore the effect and the mechanism of La^(3+) on gastric acid secretion (GAS) of isolated mouse stomach with perfused lumen, 12 cm H_2O column intragastric pressure-provided, whole stomach preparations from mice ...To explore the effect and the mechanism of La^(3+) on gastric acid secretion (GAS) of isolated mouse stomach with perfused lumen, 12 cm H_2O column intragastric pressure-provided, whole stomach preparations from mice were incubated in buffer at 37 ℃ in vitro, and perfusate was measured for pH with a pHS-3 type pH meter. The results show that La^(3+) (0.41～820×10^(-6) mol·L^(-1)) significantly promotes GAS in a concentration-dependant manner. Proglutamine, a blocker of gastrin receptor, potently inhibits GAS, and it may block the promotive effect of La^(3+) on GAS, and this effect increases with the increase of proglutamin concentration. Cimetidine, a blocker of histamine H_2 receptor, also potently inhibits GAS, and blocks the promotive effect of La^(3+) on GAS in the same manner with proglutamine. These results suggest that La^(3+) promotes GAS in isolated stomach possibly by stimulating the releases of gastrin from G cell and Histamine from ECL cell or by activating the gastrin receptors and Histamine H_2 receptors on the parietal cell, thereby accelerating the acid secretion of parietal cells in stomach.展开更多
TiO2 thin films non-uniformly doped by La^3＋ were prepared by sol-gel method. The comparison of thin film activities, which was characterized by photocatalytic degradation of methyl orange, shows that doping modes ha...TiO2 thin films non-uniformly doped by La^3＋ were prepared by sol-gel method. The comparison of thin film activities, which was characterized by photocatalytic degradation of methyl orange, shows that doping modes have great activities. The non-uniformly effects on photocatalytic doped TiO2 films resuh in good photocatalytic activities with an optimal concentration; about 0. 5% （ atom fraction ）. UV-Vis transmittance spectra indicate that the absorption edges of these TiO2 thin films shift to ward longer wave- lengths remarkably, and electrochemical behavior also reveales that e^- -h^＋ pairs are prone to formation and separation under UV irradiation. The mechanism of photocatalytic activities are enhanced by La^3＋ non-uniformly doping was discussed on the analogy of the theory of “window effect” of solar cell heterojunction.展开更多
In the retina, pH fluctuations may play an important role in adapting retinal responses to different light intensities and are involved in the fine tuning of visual perception. Acidosis occurs in the subretinal space ...In the retina, pH fluctuations may play an important role in adapting retinal responses to different light intensities and are involved in the fine tuning of visual perception. Acidosis occurs in the subretinal space （SRS） under pathological conditions such as age-related macular degeneration （AMD）. Although it is well known that many transporters in the retinal pigment epithelium （RPE） cells can maintain pH homeostasis efficiently, other receptors in RPE may also be involved in sensing acidosis, such as acid-sensing ion channels （ASICs）. In this study, we investigated whether ASICla was ex- pressed in the RPE cells and whether it was involved in the function of these cells. Real-time RT-PCR and Western blotting were used to analyze the ASICla expression in ARPE-19 cells during oxidative stress induced by hydrogen peroxide （H202）. Furthermore, inhibition or over-expression of ASICla in RPE cells was obtained using inhibitors （amiloride and PCTxl） or by the transfection of cDNA encod- ing hASICla. Cell viability was determined by using the MTT assay. The real-time RT-PCR and West- ern blotting results showed that both the mRNA and protein of ASICla were expressed in RPE cells. In- hibition of ASICs by amiloride in normal RPE cells resulted in cell death, indicating that ASICs play an important physiological role in RPE cells. Furthermore, over-expression of ASICla in RPE cells pro- longed cell survival under oxidative stress induced by H2O2. In conclusion, ASICla is functionally expressed in RPE cells and may play an important role in the physiological function of RPE cells by pro-tecting them from oxidative stress.展开更多
A 3d 4f complex [La(DMF) 6(H 2O) 3]·2H 2O (DMF=N,N dimethylformamide) was prepared and characterized by single crystal structure analysis. Single crystal X ray diffraction analysis reveals that the presen...A 3d 4f complex [La(DMF) 6(H 2O) 3]·2H 2O (DMF=N,N dimethylformamide) was prepared and characterized by single crystal structure analysis. Single crystal X ray diffraction analysis reveals that the present complex contains 3- and [La(DMF) 6(H 2O) 3] 3+ ionic pairs. The La(Ⅲ) ion is nine coordinate, and is coordinated by seven oxygen atoms of three water molecules and six DMF molecules. Each terminal CN ligand of the 3- entity is hydrogen bonded to oxygen atoms of the coordinated and lattice water molecules producing a three dimensional network. Crystal data for [La(DMF) 5(H 2O) 3]·2H 2O (C 24 H 52 CrLaN 12 O 11 =875.69): orthorhombic, space group Cmca, with lattice parameters of a =1.9346(2) nm, b =2.8902(2) nm, c =1.4825(2) nm, V =8.289(2) nm 3, Z =8, S =1.074, ρ calc =1.403 g·cm -3 , R 1=0.046, wR 2=0 117 based on 244 parameters for 5083 observed ( I >2 σ ( I )) reflections.展开更多
文摘To explore the effect and the mechanism of La^(3+) on gastric acid secretion (GAS) of isolated mouse stomach with perfused lumen, 12 cm H_2O column intragastric pressure-provided, whole stomach preparations from mice were incubated in buffer at 37 ℃ in vitro, and perfusate was measured for pH with a pHS-3 type pH meter. The results show that La^(3+) (0.41～820×10^(-6) mol·L^(-1)) significantly promotes GAS in a concentration-dependant manner. Proglutamine, a blocker of gastrin receptor, potently inhibits GAS, and it may block the promotive effect of La^(3+) on GAS, and this effect increases with the increase of proglutamin concentration. Cimetidine, a blocker of histamine H_2 receptor, also potently inhibits GAS, and blocks the promotive effect of La^(3+) on GAS in the same manner with proglutamine. These results suggest that La^(3+) promotes GAS in isolated stomach possibly by stimulating the releases of gastrin from G cell and Histamine from ECL cell or by activating the gastrin receptors and Histamine H_2 receptors on the parietal cell, thereby accelerating the acid secretion of parietal cells in stomach.
文摘TiO2 thin films non-uniformly doped by La^3＋ were prepared by sol-gel method. The comparison of thin film activities, which was characterized by photocatalytic degradation of methyl orange, shows that doping modes have great activities. The non-uniformly effects on photocatalytic doped TiO2 films resuh in good photocatalytic activities with an optimal concentration; about 0. 5% （ atom fraction ）. UV-Vis transmittance spectra indicate that the absorption edges of these TiO2 thin films shift to ward longer wave- lengths remarkably, and electrochemical behavior also reveales that e^- -h^＋ pairs are prone to formation and separation under UV irradiation. The mechanism of photocatalytic activities are enhanced by La^3＋ non-uniformly doping was discussed on the analogy of the theory of “window effect” of solar cell heterojunction.
基金supported by the National Natural Science Foundation of China (No. 81200681)
文摘In the retina, pH fluctuations may play an important role in adapting retinal responses to different light intensities and are involved in the fine tuning of visual perception. Acidosis occurs in the subretinal space （SRS） under pathological conditions such as age-related macular degeneration （AMD）. Although it is well known that many transporters in the retinal pigment epithelium （RPE） cells can maintain pH homeostasis efficiently, other receptors in RPE may also be involved in sensing acidosis, such as acid-sensing ion channels （ASICs）. In this study, we investigated whether ASICla was ex- pressed in the RPE cells and whether it was involved in the function of these cells. Real-time RT-PCR and Western blotting were used to analyze the ASICla expression in ARPE-19 cells during oxidative stress induced by hydrogen peroxide （H202）. Furthermore, inhibition or over-expression of ASICla in RPE cells was obtained using inhibitors （amiloride and PCTxl） or by the transfection of cDNA encod- ing hASICla. Cell viability was determined by using the MTT assay. The real-time RT-PCR and West- ern blotting results showed that both the mRNA and protein of ASICla were expressed in RPE cells. In- hibition of ASICs by amiloride in normal RPE cells resulted in cell death, indicating that ASICs play an important physiological role in RPE cells. Furthermore, over-expression of ASICla in RPE cells pro- longed cell survival under oxidative stress induced by H2O2. In conclusion, ASICla is functionally expressed in RPE cells and may play an important role in the physiological function of RPE cells by pro-tecting them from oxidative stress.
文摘A 3d 4f complex [La(DMF) 6(H 2O) 3]·2H 2O (DMF=N,N dimethylformamide) was prepared and characterized by single crystal structure analysis. Single crystal X ray diffraction analysis reveals that the present complex contains 3- and [La(DMF) 6(H 2O) 3] 3+ ionic pairs. The La(Ⅲ) ion is nine coordinate, and is coordinated by seven oxygen atoms of three water molecules and six DMF molecules. Each terminal CN ligand of the 3- entity is hydrogen bonded to oxygen atoms of the coordinated and lattice water molecules producing a three dimensional network. Crystal data for [La(DMF) 5(H 2O) 3]·2H 2O (C 24 H 52 CrLaN 12 O 11 =875.69): orthorhombic, space group Cmca, with lattice parameters of a =1.9346(2) nm, b =2.8902(2) nm, c =1.4825(2) nm, V =8.289(2) nm 3, Z =8, S =1.074, ρ calc =1.403 g·cm -3 , R 1=0.046, wR 2=0 117 based on 244 parameters for 5083 observed ( I >2 σ ( I )) reflections.
