An investigation was conducted using ^(45)Ca as a radioactive tracer to evaluate calcium antagonistic effects of several extracts from Bambusa Rigida in living rats.The relationship between the flavonoid and saccharid...An investigation was conducted using ^(45)Ca as a radioactive tracer to evaluate calcium antagonistic effects of several extracts from Bambusa Rigida in living rats.The relationship between the flavonoid and saccharide contents of Bambusa Rigida and calcium antagonistic effects were also analyzed.The protective effects of the alkali extracts of Bambusa Rigida on myocardial ischemia were investigated in living rats.The results indicated that the alkali extracts of Bambusa Rigida had a prominent influence on Ca^(2+) influx and efflux in the isolated rat aorta and heart,as they could obviously block ^(45)Ca entering into cells and stimulate efflux of intracellular Ca^(2+).Moreover,the alkali extracts of Bambusa Rigida had favorable protective effects on myocardial ischemia induced either by isoproterenoi injection (ISO) or by the ligation of coronary artery.These results implied that the Bambusa Rigida had attractive potential for the treatment of heart,cerebrovascular and other diseases.However,the conclusion that whether the flavonoid or saccharide in Bambusa Rigida affected the calcium antagonistic effects and Ca^(2+) channels or not was hard to make within the results of the investigation.展开更多
Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such...Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such Na/Ca exchange is characterized by quantum mechanical sensitivity. As in biological experiments radioactive 45Ca is used for the study of cold 40Ca exchange in cells and organisms, in the present work, the age-dependent effect of physiological solution (PS) containing either 40Ca or 45Ca on tissue hydration in different experimental conditions was studied in order to evaluate the bioequivalence of these two forms of Ca. The obtained data indicate that the intraperitoneal injections of 40Ca PS and 45Ca PS leading to activation of RNa/40Ca and RNa/45Ca exchanges, respectively, have different age-dependent effects on heart muscle and brain tissue hydration. As in myocyte membrane, the Na/Ca exchange is more expressed than in neuronal membrane, the age-dependent heart muscle hydration is more sensitive to quantum properties of Ca than brain tissue hydration. The [45Ca]i, in contrary to [40Ca]i, has age-dependent weakening and stabilizing effect on tissue hydration and makes the latter insensitive to ouabain. The obtained data bring us to a strong conclusion that RNa/Ca exchange has quantum mechanical properties and in biological experiments radioactive 45Ca cannot be used for adequate estimation of the functional activity of 40Ca ions in cells and organisms.展开更多
Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes...Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.展开更多
基金National Natural Science Foundation of China (Grant No.10175044).
文摘An investigation was conducted using ^(45)Ca as a radioactive tracer to evaluate calcium antagonistic effects of several extracts from Bambusa Rigida in living rats.The relationship between the flavonoid and saccharide contents of Bambusa Rigida and calcium antagonistic effects were also analyzed.The protective effects of the alkali extracts of Bambusa Rigida on myocardial ischemia were investigated in living rats.The results indicated that the alkali extracts of Bambusa Rigida had a prominent influence on Ca^(2+) influx and efflux in the isolated rat aorta and heart,as they could obviously block ^(45)Ca entering into cells and stimulate efflux of intracellular Ca^(2+).Moreover,the alkali extracts of Bambusa Rigida had favorable protective effects on myocardial ischemia induced either by isoproterenoi injection (ISO) or by the ligation of coronary artery.These results implied that the Bambusa Rigida had attractive potential for the treatment of heart,cerebrovascular and other diseases.However,the conclusion that whether the flavonoid or saccharide in Bambusa Rigida affected the calcium antagonistic effects and Ca^(2+) channels or not was hard to make within the results of the investigation.
文摘Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such Na/Ca exchange is characterized by quantum mechanical sensitivity. As in biological experiments radioactive 45Ca is used for the study of cold 40Ca exchange in cells and organisms, in the present work, the age-dependent effect of physiological solution (PS) containing either 40Ca or 45Ca on tissue hydration in different experimental conditions was studied in order to evaluate the bioequivalence of these two forms of Ca. The obtained data indicate that the intraperitoneal injections of 40Ca PS and 45Ca PS leading to activation of RNa/40Ca and RNa/45Ca exchanges, respectively, have different age-dependent effects on heart muscle and brain tissue hydration. As in myocyte membrane, the Na/Ca exchange is more expressed than in neuronal membrane, the age-dependent heart muscle hydration is more sensitive to quantum properties of Ca than brain tissue hydration. The [45Ca]i, in contrary to [40Ca]i, has age-dependent weakening and stabilizing effect on tissue hydration and makes the latter insensitive to ouabain. The obtained data bring us to a strong conclusion that RNa/Ca exchange has quantum mechanical properties and in biological experiments radioactive 45Ca cannot be used for adequate estimation of the functional activity of 40Ca ions in cells and organisms.
文摘Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.
