The effects of triton WR1339 and asialo-fetuin on the hepatic uptake of circulating native and asialo-carcinoembryonic antigen.

Uptake of carcinoembryonic antigen from the circulation of the mouse is inhibited by treatment of the animal with Triton WR1339, but not by asialo-fetuin. Uptake of asialo-carcinoembryonic antigen is inhibited by asialo-fetuin, but not by Triton WR1339. These results reflect the different mechanisms of uptake of the glycoproteins. The presence or absence of sialic acid does not seem to be important in governing Kupffer-cell uptake, but when terminal galactoses are exposed on a glycoprotein, uptake by hepatocytes is preferred. Kupffer-cell uptake of carcinoembryonic antigen is not due to the formation of high-molecular-weight complexes in the blood stream. The effect of asialo-fetuin and Triton WR1339 on the biliary excretion of carcinoembryonic antigen and asialo-carcinoembryonic antigen is discussed.