Abstract
The Gunn rat is an autosomal recessive mutant with hereditary un-conjugated hyperbilirubinemia. Hyper-bilirubinemia is considered to be due to the insufficiency of UDP-glucuronyl-transferase in the liver. Kernicterus is also caused by unconjugated hyper-bilirubinemia. In the Gunn rat, the brain lesion is characterized by marked cerebellar hypoplasia. We performed orthotopic liver (OLT) and intrasplenic fetal liver transplantation (FLT) in the rat model to supply the liver enzymes and studied its effects on bilirubin metabolism.
The serum bilirubin level decreased rapidly to the normal level after OLT. Following FLT, the serum bilirubin level decreased significantly but did not reach the normal level. The conjugated bilirubin was also increased in the bile of the Gunn rat with FLT, which suggests that the bilirubin conjugated in the transplanted fetal liver was secreted from the host liver.
On the other hand, neither OLT nor FLT was effective in correcting the cerebellar hypoplasia. These findings suggest that not only OLT but also FLT are effective procedures to supply liver emzymes, but further studies are necessary to determine the best timing of OLT or FLT for treatment of associated complications such as cerebellar degenerating changes.
