Short-term regulation of carnitine palmitoyltransferase activity in isolated rat hepatocytes.
An assay procedure for carnitine palmitoyltransferase is described which allows rapid measurement of the overt activity of this enzyme in isolated rat hepatocytes. In a one-step procedure digitonin permeabilizes the plasma membrane and at the same time carnitine palmitoyltransferase activity is measured. The use of the present procedure shows that carnitine palmitoyltransferase activity is regulated on the short term by different types of agonists. Thus, insulin, epidermal growth factor, vasopressin and the phorbol ester PMA inhibit carnitine palmitoyltransferase activity, whereas glucagon treatment renders the enzyme more active. These changes in enzyme activity coincide with corresponding changes in the rate of fatty acid oxidation.
Guzmán
M
M
Laboratory of Veterinary Biochemistry, University of Utrecht, The Netherlands.
Geelen
M J
MJ
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D004072:Digitonin / Q000494:pharmacology; D004852:Epoxy Compounds / Q000494:pharmacology; D005227:Fatty Acids / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007657:Ketone Bodies / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D010084:Oxidation-Reduction; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D004852:Epoxy Compounds; D005227:Fatty Acids; D006728:Hormones; D007004:Hypoglycemic Agents; D007657:Ketone Bodies; D010169:Palmitic Acids; D019308:Palmitic Acid; D000217:Acyltransferases; D002334:Carnitine O-Palmitoyltransferase; D004072:Digitonin; D013755:Tetradecanoylphorbol Acetate; C021756:2-tetradecylglycidic acid