Colloidal lanthanum as a marker exists in extracellular space and does not crossthe intact plasma membrane in normal condition.Consequently,it may be used todemonstrate the change of plasma membrane permeability at cellular level.Theabdominal aorta was constricted in 33 rats for 10 days,so as to establish a modelof myocardial hypertrophy.The outer and inner layers of left ventricle wall of theheart were removed and fixed immediately in 2% glutaraldehyde and 0.1 M cacody-late buffer(pH 7.4)containing 1% La(NO_3)_3 for 3 hours.In normal control tissuethe lanthanum tracer was confined to the extracellular space,basement membraneand intercalated disc.In inner layer of left ventricular wall of the experimental group,the lanthanum was deposited on the outer membrane of the mitochondria.In somemyocytes of the outer layer of left ventricular wall,their structure appearedmorphologically normal,but intracellular lanthanum appeared.Thus lanthanum canbe used as a sensitive indicator of membrane permeability in early stage of themyocardial hypertrophy.

Objective:To develop an UPLC-MS/MS method for the determination of paeoniflorin, tetramethylpyrazine, nobiletin, paeonol, amygdalin and ligustilide in Gexia-Zhuyu Decoction. Methods:Isocratic elution was carried out with mobile phase consisting of methanol- 4 mM ammonium formate. The separation was performed on Waters XTerra MS C18 (2.1 mm × 50 mm, 3.5 μm), and the mass spectrometer was operated in the positive and negative ionization electrospray (ESI) mode using multiple monitoring (MRM) for analysis of six components. Quantitative analysis by external standard method. The precursor to product ion transitions monitored for paeoniflorin, tetramethylpyrazine, nobiletin, paeonol, amygdalin and ligustilide were m/z 525.0→449.1, 137.1→55.1, 403.0→373.0, 167.2→149.4, 456.5→323.3 and 191.1→91.1, respectively. Results:Paeoniflorin, tetramethylpyrazine, nobiletin, paeonol, amygdalin and ligustilide were all analyzed exactly, the linear ranges were 0.000 2-0.012 8, 0.000 8-0.051 2, 0.000 1-0.006 4, 0.000 2-0.012 8, 0.000 6-0.038 4, 0.000 1- 0.006 4 ng, respectively. The r were 0.999 3, 0.997 5, 0.999 6, 0.992 6, 0.995 5 and 0.999 1, respectively. The recoveries of six analytes ranged from 98.00% to 105.3% and the relative standard deviations ( RSD) were all below 2.47%. Conclusions:This method was sensitive, which could be applied for the determination of paeoniflorin, tetramethylpyrazine, nobiletin, paeonol, amygdalin and ligustilide in Gexia-Zhuyu Decoction.