Effects of different nutritional conditions on chick liver mevalonate-activating enzymes.
The response of mevalonate kinase, mevalonate-5-phosphate kinase and mevalonate-5-pyrophosphate decarboxylase of chick liver to different dietary situations has been investigated. Fasting inhibited mevalonate kinase and mevalonate-5-pyrophosphate decarboxylase activities, while mevalonate-5-phosphate kinase remained practically unaltered. Refeeding after 72 h of starvation restored mevalonate kinase activity to normal levels after 120 h of refeeding. Likewise, decarboxylase activity reached normal levels at 72 h of refeeding the standard diet and slightly supranormal levels after 120 h. In addition, the sequential response of the three enzymes to a high cholesterol diet was followed throughout a 120 h period. Feeding a 5% cholesterol diet to 13-day-old chicks previously fed with a standard diet from hatching reduced considerably the activity of mevalonate-5-pyrophosphate decarboxylase, while the kinases were less affected. The present results support the idea of a coordinate regulation of the enzymes implied in cholesterol biosynthesis and suggest that mevalonate-5-pyrophosphate decarboxylase may play a significant role in this regulation.
D000818:Animals; D001711:Biotransformation; D002262:Carboxy-Lyases / Q000378:metabolism; D002645:Chickens; D002791:Cholesterol, Dietary / Q000494:pharmacology; D004032:Diet; D004041:Dietary Fats / Q000494:pharmacology; D005215:Fasting; D005502:Food; D008099:Liver / Q000201:enzymology*; D008297:Male; D008798:Mevalonic Acid / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor); D017856:Phosphotransferases (Phosphate Group Acceptor)
D002791:Cholesterol, Dietary; D004041:Dietary Fats; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C021796:mevalonate kinase; D017856:Phosphotransferases (Phosphate Group Acceptor); C022371:phosphomevalonate kinase; D002262:Carboxy-Lyases; C022503:pyrophosphomevalonate decarboxylase; D008798:Mevalonic Acid