title: Subcellular fractionation of liver organelles from phenobarbital-treated rats by counter-current partition and sucrose gradient centrifugation.
abstract: Counter-current partition, sucrose density gradient centrifugation and enzymic analysis were used to explore the changes in rat liver organelles induced by phenobarbital. There was a small increase in partition coefficient and marker enzyme activity of the endoplasmic reticulum. The modal density of the marker enzyme showed a significant decrease reflecting the proliferation of the smooth endoplasmic reticulum. The mitochondria showed a bimodal distribution with a small reduction of marker enzyme activity. In contrast, lysosomes and peroxisomes were relatively unaffected by phenobarbital treatment. Phenobarbital caused a small but statistically insignificant increase in gamma-glutamyl transferase activity: density gradient centrifugation studies indicated that the increased activity was predominantly in the biliary canalicular elements. In contrast, cytosolic gamma-glutamyl hydrolase activity was strikingly reduced by phenobarbital treatment.
mesh_terms: D015720:5'-Nucleotidase; D000118:Acetylglucosaminidase / Q000378:metabolism; D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D002499:Centrifugation, Density Gradient; D005966:Glucuronidase / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D008297:Male; D009708:Nucleotidases / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D005969:Glutamate Dehydrogenase; D009708:Nucleotidases; D015720:5'-Nucleotidase; D000520:alpha-Glucosidases; D005966:Glucuronidase; D000118:Acetylglucosaminidase; D010634:Phenobarbital