Coil planet centrifugation and its application to the observation of altered membrane properties of erythrocytes in hepatobiliary disorders.

A coil planet centrifuge (CPC) is an apparatus aiming to obtain a centrifugal force exerting on particles suspended in a fluid in a coiled polyethylene tube (coil) which makes self-rotation around its axis and revolution around the principal axis simultaneously. If a linear osmotic gradient is prepared in the coil and a small amount of blood is applied to it and subjected to centrifugation, one is able to observe the membrane properties of erythrocytes in terms of the shift of hemolysis band appearing in the coil with high accuracy and precision. Coil planet centrifugation was applied to the observation of altered membrane properties of erythrocytes in hepatobiliary diseases. Remarkable shifts of end-point of the hemolysis band going in parallel with the severity of damage were visualized. Study as to its cause revealed that increased free cholesterol content of erythrocyte membrane which was the result of plasma cholesterol Esterstürz due to inhibition of lecithin-cholesterol acyltransferase by stagnant bile acids was responsible for this phenomenon. Elevation of serum bile acid concentration and increased serum leucine-aminopeptidase were closely correlated to the shift of hemolysis end-point toward the low osmolal side. CPC may be useful for detection and chasing the clinical course of patients with hepatobiliary disorders.