Tissue distribution of intravenously injected dinitrophenylated human serum albumin. Effects of specific IgG and IgA antibodies.

After intravenous injection into mice, human serum albumin (HSA) substituted with 35 dinitrophenyl (DNP) groups per molecule rapidly became deposited on and endocytosed by non-parenchymal liver cells. Much was also found outside the reticuloendothelial system, e.g. in heart and skeletal muscle. The relative amount of circulating DNP35HSA taken up diminished with increasing amounts injected. The capacity of DNP35HSA clearance could not be saturated, however. Injection of small amounts (0.14 mg) of DNP35HSA did not result in glomerular deposition, whereas injection of slightly larger amounts (0.7 mg) did. Rabbit IgG anti-DNP increased the entrapment of DNP35HSA in the liver, whereas mouse IgA anti-DNP had less pronounced effects. DNP-HSA conjugates with lesser degree of DNP substitution, which are cleared from the blood at slower rates, became located to the liver to a lesser extent than was DNP35HSA. Rabbit IgG anti-DNP increased the amount taken up by the non-parenchymal liver cells. Mouse IgA anti-DNP did not alter the antigen distribution within the liver; that is, immune complexes formed between IgA anti-DNP and DNP-HSA became located virtually exclusively to the non-parenchymal liver cells.