Bilirubin-induced erythrocyte membrane cytotoxicity

Abstract

The kinetics of bilirubin erythrocyte interaction have been followed by scanning electron microscopy. Bilirubin-induced erythrocyte cytotoxicity embodies the interaction of the bile pigment with the outer half of the erythrocyte plasma membrane bilayer couple. This interaction leads to crenation. This membrane event appears to be primary and precedes hemolysis. The membrane crenation is dependent on the concentration of the bile pigment and is reversed by bovine serum albumin again in a concentration-dependent manner. Phospholipids do not alter bilirubin erythrocyte ineraction. Erythrocytes from jaundiced neonates show crenated surface structure in scanning electron microscopy. The crenation depends upon severity of jaundice in neonates. This suggests similarity between in vivo and in vitro mechanisms of cytotoxicity mediated by the bile pigment. Further, phototherapy reverses the process of membrane crenation. The in vivo photocatabolities isolated from urine of jaundiced neonates are nontoxic to erythrocyte membrane.