Measurement of intracellular albumin in rat liver

Abstract

An estimate of the amount of intracellular albumin in rat livers was obtained by an isotope-dilution method, in rats which had received rat [131I]albumin and been kept until equilibrium had been reached between the blood and the liver. Albumin was recovered by precipitation with antibody and dissociation in a trichloroacetic acid-ethanol mixture, from the livers after homogenization and treatment with deoxycholate, and the specific radio-activity was measured and compared with that of plasma albumin. The estimates of the intracellular albumin pool were 0.3-1.19 mg/g wet wt. In 4 of 7 experiments the value was close to 0.4 mg/g. The distribution was examined of intracellular albumin between mitochondrial and micro-somal fractions and the supernatant. At least three-quarters of the intracellular albumin was associated with the particulate fractions, and was evenly divided between the two.