Selective incorporation of asialofetuin into hepatocyte of rat.

The disposition of asialofetuin was studied in the rat. The radioactivity of 3H-asialofetuin administered intravenously disappeared rapidly from the blood. Asialofetuin was specifically and rapidly incorporated into the liver, and had no affinity toward other tissues such as the lung, spleen, heart, and kidney. Asialofetuin accumulated in the lysosomal and microsomal fractions of the rat liver cells immediately after administration, shifted to the low dense fraction (cytosol fraction) with the elapsing of time, and was possibly digested by lysosomes. The elimination of 3H-asialofetuin from the liver was fast and the degradates excreted into the bile and urine represented 90 per cent of the dose administered by 180 min following administration. It was suggested that asialofetuin functions as a carrier of drugs to the liver, especially to hepatocytes.