[Mechanism of action of ginsenoside Rb1 in decreasing intracellular Ca2+].
Using fluorescent probe Fura-2/AM, ginsenoside Rb1 (10, 50 and 100 mumol.L-1) was shown to dose-dependently reduce intracellular Ca2+ concentration of freshly dissociated brain cells isolated from newborn rats. It was also found to increase the fluidity of synaptosome membrane impaired by FeSO4-Cystein. Rb1 (10 mumol.L-1) shifted the dose-response curve to the right and decreased the maximal response in isolated mouse tail artery. Rb1 (10 and 100 mumol.L-1) was also found to reduce 5-HT-induced contraction of isolated rat basilar artery. With the whole-cell patch clamp technique, Rb1 (100 mumol.L-1) was shown to have no obvious effect on calcium current and potassium current. However, Rb1 was shown to increase Na(+)-K+ ATPase and Ca(2+)-Mg2+ ATPase activities at low dose in rat cerebral cortical synaptosomes. The results indicate that decrease of [Ca2+]i by Rb1 may be attributed to increase of ATPase activity.
Jiang
X Y
XY
Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing.
Zhang
J T
JT
Shi
C Z
CZ
D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002491:Central Nervous System Agents / Q000494:pharmacology*; D036145:Ginsenosides; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013570:Synaptic Membranes / Q000187:drug effects; D013574:Synaptosomes / Q000201:enzymology
D002491:Central Nervous System Agents; D036145:Ginsenosides; D012503:Saponins; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium