Influence of cycloheximide on normal and induced delta-aminolevulinic acid synthetase (aminoketone synthesis) of rat liver in vivo and in vitro.
2 and 5 mg/kg cycloheximide given i.p. 30 minutes prior to the inducer allylisopropylacetamide (AIA) diminished or prevented the enhancement of delta-aminolevulinic acid synthetase (ALAS) activity in newborn rats. In adult rats the small AIA effect 24 hours after pretreatment was enhanced by 2 mg/kg cycloheximide i.p., when the inhibitor was injected 2 hours prior to the inducer. The basic aminoketone synthesis was inhibited by cycloheximide alone. 150-600 microgram/ml cycloheximide had no effect on the aminoketone synthesis of rat liver slices in vitro during 4 hours of incubation. The in vitro induction by 0.6 mg/ml AIA was enhanced by cycloheximide, if the inducer was added 1 hour after preincubation with cycloheximide. It is supposed, that the cytoplasmically localized precursor-ALAS is activated at the beginning of the induction process prior to the initiation of de novo enzyme synthesis, at least in vitro.
D000624:5-Aminolevulinate Synthetase / Q000378:metabolism*; D000096:Acetone / Q000031:analogs & derivatives / Q000096:biosynthesis; D000502:Allylisopropylacetamide; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology*; D004790:Enzyme Induction; D005260:Female; D008099:Liver / Q000201:enzymology*; D008297:Male; D051381:Rats; D013997:Time Factors
D000096:Acetone; D000502:Allylisopropylacetamide; D003513:Cycloheximide; D000624:5-Aminolevulinate Synthetase