Effect of phenylalanine derivatives on the main regulatory enzymes of hepatic cholesterogenesis

✍ Scribed by M. Castillo; M. Martinez-Cayuela; M. F. Zafra; E. Garcia-Peregrin

• Book ID: 104674123
• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 333 KB
• Volume: 105
• Category: Article
• ISSN: 0300-8177
• DOI: 10.1007/bf00230371

✦ Synopsis

Phenylalanine, phenylpyruvate and phenylacetate produced a considerable inhibition of chick liver mevalonate 5-pyrophosphate decarboxylase while mevalonate kinase and mevalonate 5-phosphate kinase were not significantly affected. Phenolic derivatives of phenylalanine produced a similar inhibition of decarboxylase activity than that found in the presence of phenyl metabolites. The degree of inhibition was progressive with increasing concentrations of inhibitors (1.25-5.00 mM). Simultaneous supplementation of different metabolites in conditions similar to those in experimental phenylketonuria (0.25 mM each) produced a clear inhibition of liver decarboxylase and 3-hydroxy-3-methylglutaryl-CoA reductase. To our knowledge, this is the first report on the in vitro inhibition of both liver regulatory enzymes of cholesterogenesis in phenylketonuria-like conditions. Our results show a lower inhibition of decarboxylase than that of reductase but suggest an important regulatory role of decarboxylase in cholesterol synthesis.