Abstract.Total activity of aspartate‐aminotransferase (GOT; EC 2.6.1.1) and activities of the cytoplasmic (c‐GOT) and mitochondrial (m‐GOT) isozymes were measured in rat liver 24 and 48 h after bilateral nephrectomy.24 h after nephrectomy no significant differences in enzyme activities could be detected between uraemic animals and sham‐operated controls. However 48 h after nephthrectomy the total activity of GOT increased significantly. Fractional tissue extraction revealed an elevation of only the cytoplasmic isozyme (c‐GOT), due to a selective increase of this enzyme fraction. No significant change could be noticed of the mitochondrial isozyme (m‐GOT). These results are discussed with regard to an increased gluconeogenesis in rat liver 48 h after bilateral