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
The influence of La 3+ on lactate dehydrogenase catalysis was investigated by electrochemical and FT-Raman techniques. The results showed that La 3+ ions bind preferably with phosphate moiety and ribose group (3′-OH)...The influence of La 3+ on lactate dehydrogenase catalysis was investigated by electrochemical and FT-Raman techniques. The results showed that La 3+ ions bind preferably with phosphate moiety and ribose group (3′-OH) connected to nicotinamide in coenzyme NAD +/NADH, destabilize the enzyme-coenzyme complex and inhibit LDH activity.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The influence of La 3+ on lactate dehydrogenase catalysis was investigated by electrochemical and FT-Raman techniques. The results showed that La 3+ ions bind preferably with phosphate moiety and ribose group (3′-OH) connected to nicotinamide in coenzyme NAD +/NADH, destabilize the enzyme-coenzyme complex and inhibit LDH activity.
