6 research outputs found
Experimental study of WGA binding on the endothelial cell surface in cerebral ischemia
The relationship between the saccharide chain
on the endothelial cell surface and the permeability of
intracerebral blood vessels has been studied. In the present
study, wheat germ agglutinin (WGA) was perfused into
capillaries in the area postrema of the normal Mongolian
gerbil, where the blood brain barrier (BBB) is known to
lack, and into intracerebral blood vessels, the BBB of
which had been destroyed by experimentally induced brain
ischemia. The light microscopic features of the sections
from WGA-perfused brain tissues of the normal gerbil
revealed that most of the blood vessels, including
capillaries in the brain parenchyma, showed positive
findings (the reaction induced a very distinct staining of
the vascular wall) from which the course and structure of
the fine vessels could be determined. The reaction to WGA
on the diaphragma fenestra (DF) in capillaries in the area
postrema was relatively weak, and DF without the reaction
were occasionally revealed by electron microscopy. The
gerbil, in which cerebral ischemia had been induced, also
showed partial defect of the reaction with WGA on the
lumina1 side of the endothelial cells. The results of the
present experiment suggest some degree of correlation
between the saccharide chains, including the specific
monosaccharide of WGA, on the endothelial cell surface
and permeability. It was considered that lectin can be used
as an index for morphological observations, suggesting an
alteration in function of the endothelial cell membrane.
In addition, the perfusion method in this experiment
suggested the possibility of distinguishing pinocytotic
vesicles from pits of cell membranes
Lectin , UEA- 1, reaction of capillary endothelium with reference to permeability in autopsied cases of cerebral infarction
The relationship between endothelial reactivity
to Ulex europaeus agglutinin-1 (UEA-I) and the
permeability of the vascular wall in human autopsied cases
ol' cerebral infarction was studied. Sections from the
cerebral cortex were reacted with horseradish peroxidase
UEA-1 to demonstrate the surface membrane of endothelial
cells. Albumin in the neuropil of sections was de~nonstrated
for the estimation of increased vascular permeability. The
results showed that endothelial reactivity to UEA-I was
reduced in cases where death had occurred 3 to 5 days after
onset of cerebral infarction. Reactivity was also diminished
in cases where death had occurred after 13 and 25 days;
these cases showed fresh ischemic lesions caused by reattacks
of infarction. Albumin extravasation into the
neuropil was demonstrated in these intermediate cases.
Chronic cases, dying after more than 52 days, showed no
reduction of endothelial reactivity to UEA-I and no
albumin extravasation was proved.
It was concluded that UEA-1 can be employed as a
useful n~orphological marker for evaluation of endothelial
function and vascular permeability