Auditory brainstem response and unbound bilirubin in jaundiced (jj) Gunn rat pups

The role of plasma bilirubin-albumin binding in the pathogenesis of kernict erus in human newborns is controversial. Kernicterus in the jaundiced (jj) Gunn rat pup, an animal model for kernicterus, prolongs interwave intervals and decreases wave amplitude in the auditory brainstem response (ABR). Pla sma total bilirubin concentration (TBC), albumin concentration, and unbound bilirubin concentration (UBC), a measure of bilirubin-albumin binding, wer e measured in 16-day-old jj Gunn rat pups (n = 21) and compared with ABR wa ve latencies, interwave intervals, and wave amplitudes by linear correlatio n. The UBC, but not the TBC or TBC/albumin ratio, correlated positively and significantly with ABR I-II and I-III interwave intervals (r = 0.55, p = 0 .009, and r = 0.60, p = 0.004, respectively). The UBC, but not the TBC or T BC/albumin ratio, predicts bilirubin toxicity, as measured by bilirubin-ind uced ABR changes in jj Gunn rat pups. Copyright (C) 2001 S. Karger AG, Base l.