Evidence for in vivo hepatic uptake of a galactose-terminated glycoprotein in fish (Salmo alpinus L.).

125I-labelled asialofetuin injected intravenously into chars (Salmo alpinus L.) was cleared from the blood with a half-time of approx. 60 min. The injected asialofetuin was found to be accumulating in the liver when different organs were dissected out at various time points after the injection. 125I-labelled fetuin was not concentrated in the liver, and the uptake of 125I-labelled asialofetuin was almost completely inhibited by simultaneously injecting an excess unlabelled asialofetuin, indicating a specific uptake mechanism for the galactose-terminated glycoprotein in char liver. Denatured human serum albumin was not taken up by the liver, but was recovered in the kidneys, suggesting that the liver in char is devoid of macrophages. It therefore seems reasonable to assume that the injected 125I-labelled asialofetuin is taken up by the parenchymal cells of the char liver.