In these experiments, the role of the spleen in
endotoxin-induced liver injury was evaluated, using rats which underwent
splenectomy or splenic vein
ligation with antecedent spleno-systemic shunt. Male Wistar rats were divided into three groups: a
sham-operated group, a
splenectomy group, and a splenic vein
ligation group. In each animal, 48 h after surgery, 5 mg/kg
lipopolysaccharide (LPS) were injected intravenously. Six rats from each group were sacrificed 6 or 12 h after LPS administration. Bronchoalveolar lavage fluid (BALF) and arterial blood were also collected.
Splenectomy reduced the liver injury as indicated by the serum
lactate dehydrogenase level. A decrease in liver tissue
adenosine triphosphate and increase in
lipid peroxide were induced by LPS administration and inhibited by
splenectomy.
Splenectomy also reduced alveolar
protein release as indicated by the
protein level in BALF. Splenic vein
ligation provided similar protective effects on the liver, but did not affect
lung injury. From these results, it appears that the spleen plays a significant role in
endotoxin-induced liver injury, and a mediator derived from the spleen is likely associated with development of liver injury. This mediator may be cleared or inactivated by not only
splenectomy but also splenic vein
ligation.