Abstract
The purpose of this investigation was to examine the effect of gram-negative bacterial lipopolysaccharide on hyaluronan concentration in blood plasma, hyaluronan removal from the blood and hyaluronan uptake by isolated, perfused rat liver. Intravenous administration of Escherichia coli lipopolysaccharide to rats markedly increased plasma hyaluronan concentration in a dose-dependent manner. One day after lipopolysaccharide challenge (0.1 or 1.0 mg per 100 gm body wt), plasma hyaluronan levels were 570.7 +/- 66.8 ng x ml-1 and 1,951.0 +/- 120.3 ng x ml-1, respectively, as compared with 94.2 +/- 12.2 ng x ml-1 in the time-matched control animals. Removal of intravenously injected hyaluronan (30 micrograms per 100 gm body wt) was suppressed 32% by lipopolysaccharide administration (100 micrograms per 100 gm body wt). At the same dose, lipopolysaccharide induced a severe inhibition (60% to 80%) of hyaluronan uptake by perfused livers isolated 3 or 24 hr after lipopolysaccharide administration. The inhibitory effect of lipopolysaccharide on hyaluronan uptake by the isolated, perfused liver was not abolished by pretreatment with either antibodies to tumor necrosis factor-alpha IgG or indomethacin, an inhibitor of the cyclooxygenase pathway. Continuous intravenous infusion of recombinant murine tumor necrosis factor-alpha for 18 to 20 hr did not affect plasma hyaluronan concentration. These data suggest that neither tumor necrosis factor-alpha, an early cytokine induced by lipopolysaccharide, nor prostaglandins are involved in the mechanism of lipopolysaccharide-induced inhibition of hyaluronan uptake by the perfused rat liver.(ABSTRACT TRUNCATED AT 250 WORDS)
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