Effect of irradiation on the erythrocyte membranes of homozygous Gunn rat sucklings.

Erythrocyte membranes were isolated from irradiated Gunn's strain of jaundiced rat sucklings, and photodynamic action of bilirubin in vivo was investigated using sodium dodecyl sulfate-polyacrylamide-gel electrophoresis. The effectiveness of irradiation was verified in terms of decrease of plasma bilirubin concentrations and cerebellar bilirubin contents, and also by recovery from the cellbellar hypoplasia, a characteristic feature of the homozygotes (j/j). The cross-linking of erythrocyte membrane proteins by photodynamic action of bilirubin was demonstrated in vitro in rat erythrocytes as reported for human erythrocytes by Girotti (Biochemistry 14: 3377, 1975). The phenomenon, however, was not observed in vivo. Instead, a protein band with a mol. wt. of 32,000 was increased by the irradiation both in the homozygous (j/j) and heterozygous (j/+) Gunn rats.