Transient hyperammonemia during aging in ornithine transcarbamylase-deficient, sparse-fur mice.
Ornithine transcarbamylase [EC 2.1.3.3] (OTC) deficient, sparse-fur (spf) mice are considered to be a good model of human OTC deficiencies. We measured the blood ammonia concentration in spf mice. It was not always at a high level. It was high only during weaning, then gradually decreased and finally fell to a normal level. A similar phenomenon was observed in the change of hepatic ammonia concentration. Excretion of urinary orotate in spf mice was 15-20 times higher than in control mice just after weaning. It also gradually decreased during aging, but remained at a high level compared with adult control mice. OTC activity at pH 7.7 in the liver of spf mice increased significantly between the weaning period and 30-40 days old, when blood ammonia was falling to a normal level.
D000375:Aging; D000641:Ammonia / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001835:Body Weight; D004195:Disease Models, Animal; D006197:Hair / Q000502:physiology*; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains / Q000254:growth & development*; D009954:Ornithine Carbamoyltransferase / Q000378:metabolism; D020163:Ornithine Carbamoyltransferase Deficiency Disease; D009963:Orotic Acid / Q000652:urine; D014508:Urea / Q000097:blood / Q000378:metabolism
D009963:Orotic Acid; D000641:Ammonia; D014508:Urea; D009954:Ornithine Carbamoyltransferase