Urea cycle enzyme activities are normal and inducible by a high-protein diet in CCl4 cirrhosis of rats.
We produced moderately severe, inactive micronodular cirrhosis in rats using CCl4 and measured the urea cycle enzyme activities in liver after feeding a 15% casein diet for 1 week and again after a 60% casein diet for 1 week. There was no deficiency of any of the five urea cycle enzymes in cirrhotic livers of rats pair-fed the 15% casein diet. Argininosuccinate synthetase and carbamyl phosphate synthetase activities were lower than in non-pair-fed controls by some baselines. All five enzymes in cirrhotic livers were induced 1.5- to 3-fold by the high-protein diet expressed as units per 100 gm of rat. The level of carbamyl phosphate synthetase activity was lower in the livers of rats pair-fed the 60% casein diet than in control livers based on wet weight, collagen-free protein and DNA, but the activities were equal expressed as units per 100 gm of rat. This example of CCl4-induced cirrhosis in the rat does not serve as a good model for human cirrhosis, in which the urea cycle enzymes are reported to be decreased in activity.
Snodgrass
P J
PJ
Veterans Administration Medical Center, Indianapolis, Indiana 46202.
D000818:Animals; D002251:Carbon Tetrachloride; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D014508:Urea / Q000378:metabolism*
D004044:Dietary Proteins; D014508:Urea; D002251:Carbon Tetrachloride