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Partial subcellular distribution and specifically the incorporation of 35SO4 in the Golgi apparatus of rat liver was studied. The isolated Golgi fraction was placed on a further sucrose gradient for subfraction and in all samples the total incorporated label, the trichloroacetic-acid-soluble and insoluble, and chloroform/methanol-soluble and insoluble amounts of label were measured. Approximately 2.3% of the total injected 35S was found in the liver, of which 2% was localized in the isolated Golgi fraction. Further subfractionation of the Golgi has shown that the majority of the 35S is localized at densities 1.12-1.13 g/cm3 in the gradient. In the isolated Golgi fraction 85% of the label was present in the trichloroacetic-acid-soluble and 15% in the insoluble part. Approximately 1% of the label in the Golgi fraction was soluble in chloroform/methanol. On the bases of radioactivity per weight of protein and total radioactivity, the Golgi fractions had the highest activity, except the first supernatant which had higher radioactivity. Briefly, a significant amount of the 35SO4 can be found in the isolated rat liver Golgi 15 min after the injection of the label, and the majority of this label is localized in the material sedimenting at density 1.12-1.13 g/cm3 after subfractionation of the Golgi apparatus.

Activity changes of enzymes in isolated rat liver Golgi preparations at different times (1-48 h) after a short ether anesthesia are reported. Activity of galactosyl-transferase showed a slight gradual increase but thiamine pyrophosphatase decreased sharply, and after 24 h increased to above control level. Arylsulphatase-A remained largely unchanged, and B was significantly decreased. Acid phosphatase activity did remain at the control level, but alkali phosphatase showed a gradual and highly significant increase. Five other enzymes representing probable contaminations from other subcellular organelles, have also been assayed. Correlation is sought between the enzyme activity changes and some other metabolic effects of anesthesia.

Rats were injected with a single intravenous dose of aminonucleoside (AMN) and sacrificed 1-48 h later. The activity of several enzymes was assayed in the Golgi apparatus isolated from the liver. Galactosyltransferase activity showed little changes after the AMN, but both acid (EC 3.1.3.2) and alkaline phosphatase (EC 3.1.3.1) activities increased within the first hour and reached control levels only 5-24 h later. Thiamine pyrophosphatase and arylsulfatase A (EC 3.1.6.1) activities also increased and stayed at higher levels for the duration of the experiment. Arylsulfatase B (EC 3.1.6.1) activity decreased shortly after the AMN but later increased to above control levels. These findings support earlier results in which liver ultrastructural and biochemical changes were observed early before renal lesions and proteinuria.