This study was carried out to investigate the adherence of the neutrophils and endothelia cells induced by E. coli lipopolysaccaride(LPS), effects of tunicamycin on the adhesion of both cells, and fine structures of adhesion sites. The
experiments
were
divided four parts. The experiment I was to study the fine structures of adhesion sites. The Sprague-Dawley rats were intraperitoneally injected 4mg/kg of LPS. The lungs were examined by electron microscopy with ruthenium red stain. The
experiment
II
was to evaluate the adherence of neutrophils and endothelial cells after exposure of LPS to the neutrophils or endothelial cells. The experiment III was to investigate the effects of tunicamycin on LPS-induced adherence of neutrophils and
endothelial
cells. And experiment IV was on in vitro study to evalute the LPS-induced adherence of both cells and the effects of tunicamycin on the adherence of both cells after exposure of LPS. The results were as follows:
On electron microscopy, there were perpendicular fibrillar structures between the neutrophil and endothelial cell in adhesion sites with 15-20nm of interspaces and between the neutrophils with 25-30nm in gap.
Adherence of neutrophils on the alveolar capillary endothelial cells per. 1,000 m2 of pulmonary parenchyme was 1.24±1.03 in non-treated control group, 5.24±3.22 in group of LPS-treated
endothelium, 3.78±1.63 in LPS-treated neutrophil, 5.11±2.84 in LPS-treated endothelium and
neutrophil(p<0.01). The neutrophil adherence was 0.93±0.85 in group of LPS-treated endothelium and tunicamycin and LPS-treated neutrophil, 2.53±1.60 in tunicamycin and LPS-treated endothelium and neutrophil(p<0.01). In cases of culture,
neutrophil
adherence was 9.47±2.68 in non-treated control group, 13.37±3.84 in LPS-treated endothelium, 10.67±2.66 in tunicamycin and LPS-treated endothelium, and 13.40±3.39 in tunicamycin and LPS-treated endothelium and neutnophil(p<0.01). According to
the
above results, it is concluded that stimulation of the endothelium is an importan factor in neutrophil adherence to endothelium induced by LPS, and that tunicamycin significantly suppress the neutrophil adhesion in the state of LPS stimulation.
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