Galactose metabolism in regenerating rat liver.
1. Rats trained on a controlled lighting and feeding schedule were subjected to partial hepatectomy or sham operation. 2. After a large period of about 6h the activity of UDP-galactose 4-epimerase increased threefold, reaching a maximum 4 days after partial hepatectomy, and returned to normal values within a fortnight. 3. The enzyme pattern of the UDP-galactose-glycoprotein galactosyltransferase was biphasic, one peak appearing at 20 h, the second at 72 h after partial hepatectomy. 4. The rise in enzyme activities could be blocked by the injection of actinomycin D, and the Km values for UDP-glucose and UDP-galactose were nearly identical in regenerating and adult liver. It is therefore concluded that the increase in enzyme activity is due to synthesis de novo of enzyme protein.
D000818:Animals; D002940:Circadian Rhythm; D003609:Dactinomycin / Q000494:pharmacology; D005690:Galactose / Q000378:metabolism*; D005700:Galactosyltransferases / Q000378:metabolism; D006498:Hepatectomy; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008115:Liver Regeneration; D008297:Male; D009713:Nucleotidyltransferases / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D013997:Time Factors; D014534:UDPglucose 4-Epimerase / Q000378:metabolism; D014531:Uridine Diphosphate Galactose / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
D011506:Proteins; D003609:Dactinomycin; D014531:Uridine Diphosphate Galactose; D005700:Galactosyltransferases; D010770:Phosphotransferases; D009713:Nucleotidyltransferases; D014534:UDPglucose 4-Epimerase; D014532:Uridine Diphosphate Glucose; D005690:Galactose