Effect of recombinant human interleukin 1β (rhIL-1β) on amino acid flux in the isolated perfused rat liver.

We studied the effect of recombinant human IL-1β (rhIL-1β) on hepatic amino acid (AA) flux in the isolated perfused rat liver model. Two experimental groups were used - a control group (n = 5) and a rhIL-1β-treated group (n = 5). IL-1 was added to the perfusate in two successive boluses of 0.1µg and 0.9µg, respectively 35 min (final concentration 0.67 ng/ml) and 60 min (6 ng/ml) after beginning the perfusion. In the IL-1 treated group, a reduction in flux was observed for only three AA, alanine, phenylalanine and serine. Glucose and urea production in the IL-1-treated group was slightly but not-significantly lower than in the controls.rhIL-1β thus has only minor direct effects on AA flux and gluconeogenesis in the liver and cannot therefore be held responsible for the increase in hepatic amino acid uptake during stress.