ABSTRACT
OBJECTIVE: To observe the cellular mechanism of A II inhibition on Maxi-conductance calcium activated potassium channel (BKCa) in ECV304 cell membrane. METHOD: Using the cell-attached configuration of patch clamp technique. RESULTS: A II receptor antagonist saralasin (10(-7) mol/L) may block the inhibitory effect of A II (10(-7) mol/L). Phorbol ester (5 x 10(-8) mol/L) potentiated the effect of A II, while NO (10(-10) mol/L SNP) decreased the effect of A II and gingko leaf extract (800 micrograms/ml) activated BKCa and opposed the effects of A II. CONCLUSION: A II receptor mediates the inhibitory effect of A II on BKCa in ECV304, and PKC is involved in this inhibition. NO and ginkgo leaf extract protect BKCa from the inhibition of A II.
Subject(s)
Angiotensin II/pharmacology , Drugs, Chinese Herbal/pharmacology , Ginkgo biloba/chemistry , Potassium Channels, Calcium-Activated/drug effects , Cells, Cultured , Humans , Nitric Oxide/pharmacology , Patch-Clamp Techniques , Plant Leaves/chemistry , Potassium Channels, Calcium-Activated/physiology , Protein Kinase C/physiology , Receptors, Angiotensin/physiology , Umbilical Veins/cytologyABSTRACT
OBJECTIVE: To observe the action of minimally modified low density lipoprotein (mm-LDL) on BKCa in ECV304 cell and the interfering effects of radix salviae miltiorrhizae extract powder 764-3 (30 micrograms/ml) and lingustrazine (200 micrograms/ml) on this action. METHOD: The cell-attached configuration of patch clamp technique was applied. RESULTS: mm-LDL (100 micrograms/ml) potentiated the activity of BKCa in ECV304. While 764-3 and lingustrazine abolished it. CONCLUSIONS: mm-LDL acted on vascular endothelial cell ECV304 could rapidly activate the activity of BKCa and might result in the increase of electro-chemical gradient for the resting Ca2+ influx, thus resting cytoplasmic concentration of calcium could be elevated and endothelial dysfunction would be induced. 764-3 and lingustrazine might have the protective action through decreasing the activity of BKCa.
Subject(s)
Ligusticum , Lipoproteins, LDL/pharmacology , Plant Preparations/pharmacology , Potassium Channels, Calcium-Activated/drug effects , Salvia miltiorrhiza , Cells, Cultured , Drug Antagonism , Humans , Umbilical Veins/cytologySubject(s)
Anti-Bacterial Agents/isolation & purification , Nocardia/analysis , Rifamycins , Anti-Bacterial Agents/pharmacology , Chemical Phenomena , Chemistry , Microbial Sensitivity Tests , Models, Molecular , Naphthoquinones , Streptococcus pneumoniae/drug effects , Streptococcus pyogenes/drug effects , Streptococcus sanguis/drug effectsABSTRACT
Kanglemeisu A (C50H63O19B.CH3OH) is the product of an actinomyces species from a soil sample gathered in China Kanglemeisu A belongs to the triclinic system, space group P1, unit cell: a = 12.760(3), b = 10.287(2), c = 9.926(2) A, alpha = 88.39(2), beta = 78.64(2), gamma = 89.14(2). RANTAN direct method is used to solve the structure. The final discrepancy factor is R = 0.0689, after atom coordinates and temperature factors have been refined with full matrix least squares. The structure skeleton consists of four parts, the naphthalene nucleus connected to the 5-membered ring, a 17-membered ring connected to C2, a dimethyl butane diacid extended out from C20, beta-D-3,4-OO' methylenedigitoxose passing through an oxygen bridge O6 and linked to C27 of ansa ring.
