RESUMEN
Antigen contents of ornithine transcarbamylase (OTC) protein in the liver of 5 patients with OTC deficiency and mutant mice were studied by ELISA. OTC activities in the liver tissues of 2 patients were 13.1% and 5.2% of the controls, respectively. The 2 patients' antigen contents of OTC protein were decreased in parallel with the enzyme activities. OTC antigen contents were not detected in the liver tissues of remaining 3 patients who had the complete type of OTC deficiency. Enzyme activities, kinetic properties and antigen contents of the OTC deficient mutant mice were the same as the results reported previously (Briand et al. 1982). The ELISA method for the assay of OTC antigen contents used in this study is more sensitive as compared with the radial immunodiffusion technique.