Effects of colchicine on the synthesis and transport of albumin: a combined electron cytochemical and autoradiographic study

We investigated the intracellular transport of albumin in the livers of rats treated with colchicine using immunoperoxidase study as well as combined immunoelectron microscopy and autoradiography with [3H]-leucine. Immunoreaction of albumin was observed in all hepatocytes. Its subcellular location was in the rough endoplasmic reticulum, Golgi apparatus and lysosomes. After the injection of [3H]-leucine through the portal vein, a combined technique revealed accumulated grains on the albumin-positive Golgi apparatus or the albumin-positive vesicles in the vicinity of the Golgi apparatus. These findings suggest that albumin transport from the Golgi apparatus to sinusoids is disturbed by colchicine. Enzyme histochemistry showed many acid phosphatase-positive lysosomes in hepatocytes of the liver treated with colchicine. Albumin retained in the vicinity of the Golgi apparatus may be digested by lysosomes. An in situ hybridization study with isotopes revealed the presence of silver grains for albumin mRNA in all hepatocytes of livers treated or untreated with colchicine; there was no significant difference in the number of silver grains in the two groups. Therefore, colchicine has very little effect on albumin synthesis in the liver.