Endotoxemia and brain bilirubin in the rat

To investigate the possible role of sepsis with endotoxemia in kernicterus, we studied the effect of endotoxin on accumulation of bilirubin and albumin in rat brain. Male Sprague-Dawley rats were given Escherichia coli endotoxin i.v. After 150 min 10 microCi 125I-bovine serum albumin was given intravenously, followed by a 1-hour bilirubin infusion. Brain bilirubin was significantly higher in the endotoxin group than in the controls (1.34 +/- 0.47 vs. 0.83 +/- 0.31 microgram/g, p < 0.05). However, the difference between the ratios of brain bilirubin to total serum bilirubin at the time of sacrifice were not significant. Total and unbound bilirubin values were significantly higher in the endotoxin-treated group at 165 min. Endotoxemia increased the net accumulation of bilirubin in rat brain, but this increase was probably secondary to an increase in total and unbound bilirubin, rather than an increase in the transfer per se of bilirubin across the blood-brain barrier.