硝酸镧作为示踪剂显示肥大心肌细胞膜通透性的改变

LANTHANUM NITRATE AS A MARKER TO DEMONSTRATE THE PERMEABILITY OF PLASMA MEMBRANE IN MYOCARDIAL HYPERTROPEY

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.