Different induction of microsomal carboxylesterases, palmitoyl-CoA hydrolase and acyl-L-carnitine hydrolase in rat liver after treatment with clofibrate.
The levels of hepatic carboxylesterases, including palmitoyl-CoA hydrolase and decanoyl-D,L-carnitine hydrolase, were studied in total homogenates and subcellular fractions prepared from the livers of male rats fed diets containing 0.3% clofibrate. The microsomal carboxylesterase as well as the fatty acyl-thioesterase are differently induced by clofibrate feeding. The specific activities of acetanilide carboxylesterase and decanoyl-D,L-carnitine hydrolase increased more than 3-fold in the microsomal fraction, compared to pellet-fed control animals. The microsomal activities of palmitoyl-CoA hydrolase and propanidid hydrolase were decreased by about 20 to 40% in clofibrate-treated rats. The specific clofibrate hydrolase activity remained unchanged after clofibrate administration, indicating that this microsomal carboxylesterase is not induced by its own substrate. The data suggest a different distribution of the differing carboxylesterase along the endoplasmic reticulum.
D000083:Acetanilides / Q000378:metabolism; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis*; D002331:Carnitine / Q000031:analogs & derivatives / Q000378:metabolism; D002994:Clofibrate / Q000494:pharmacology*; D004790:Enzyme Induction; D007526:Isoelectric Point; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D010170:Palmitoyl-CoA Hydrolase / Q000096:biosynthesis*; D011410:Propanidid / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013869:Thiolester Hydrolases / Q000096:biosynthesis*
D000083:Acetanilides; C002893:decanoylcarnitine; D010171:Palmitoyl Coenzyme A; D011410:Propanidid; D002265:Carboxylic Ester Hydrolases; C019843:acylcarnitine hydrolase; D013869:Thiolester Hydrolases; D010170:Palmitoyl-CoA Hydrolase; D002994:Clofibrate; D002331:Carnitine