A Gunn rat model of preterm hyperbilirubinemia.

ABSTRACT

BACKGROUND: The impact of bilirubin in preterm infants is poorly understood. An animal model would assist in improving understanding. The Gunn rat lacks uridine diphosphate-glucuronylsyl transferase 1 and can be made acutely hyperbilirubinemic by injection of sulfodimethoxine (sulfa), a drug that displaces bilirubin from albumin and thus increases free bilirubin. METHODS: On postnatal day (P) 5, Gunn rats either heterozygous (Nj) or homozygous (jj) for glucuronosyltransferase activity were injected with either saline or sulfa. Behavior and cerebellar weight were measured. RESULTS: Pups did not show any signs of acute bilirubin encephalopathy. Pup weight dropped significantly on P8 only in the jj-sulfa group. Behavior was affected only in the jj-sulfa group. Cerebellar weight was significantly less in the jj-sulfa group. CONCLUSION: The Gunn rat pup model may be a good model to study hyperbilirubinemia in preterm infants.