Haemolysis in experimental cholestasis: possible role of erythrocyte sialic acid.

Because previous studies have suggested that red cell membrane sialic acid might be a determinant of survival in vivo, we examined the relationship between haemolysis, erythrocyte membrane sialic acid, and hepatic neuraminidase (sialidase) levels in experimental cholestatic jaundice in rats. Treatment of normal rat erythrocytes with neuraminidase in vitro resulted in a significant reduction in their survival in vivo and removal by the spleen. The degree of haemolysis was comparable to that previously found 12 days after bile duct ligation in rats. Bile duct ligation resulted in a significant increase in hepatic neuraminidase and a decrease in erythrocyte sialic acid. The findings are consistent with the hypothesis that one or more neuraminidases present in inreased amounts in the bile duct-ligated livers are responsible for the removal of sialic acid from circulating erythrocytes and subsequent removal of these cells in the spleen.