Enzyme activity in liver

Table I. Drug-metabolizing enzyme activities in liver of animals.

Table 4.6.14 shows the enzyme activities in liver, muscle, and fibroblasts. 

DeVito MJ, Diliberto JJ, Ross DG, et al. 1997. Dose-response relationships for polyhalogenated dioxins and dibenzofurans following subchronic treatment in mice. I. CYP1A1 and CYP1A2 enzyme activity in liver, lung, and skin. Toxicol Appl Pharmacol 147 267-280. 

Scherst n, T., Wahlqvist, L., and Johansson, L.-G., Lysosomal enzyme activity in liver tissue from patients with renal carcinoma. Cancer 23, 608-613 (1969). 

FIGURE 8.15 Enzyme activity versus level of protein in the diet. Eadi point represents enzyme activity in livers from rats fed the indicated diet. (Redrawn with permission from Peters and Harper, 1985.)... 

Because the pattern and degree of elevation of enzyme activity vary with the type of liver disease, their measurement is extremely helpful in the recognition and differential diagnosis of liver damage. A number of factors govern the ability of Uver enzymes to assist in diagnosis including their (1) tissue specificity, (2) subcellular distribution, (3) relative activity of enzyme activity in liver and plasma, (4) patterns of release, and (5) clearance from plasma. 

Ornithine carbamoyltransferase (ornithine transcar-bamylase) (EC 2.1.3.3). Gross elevation of blood ammonia. Elevated glutamine in plasma and cerebrospinal fluid. Urea excretion low. Urinary orotic add increased. Uracil and uridine in urine. Gene for enzyme X-linked. Condition severe in boys (0-0.2% of normal enzyme activity in liver), who die in postnatal period (some cases of late onset have been reported). Girls have 5-10% normal liver enzyme activity. Some girls have died in late infancy or childhood, and others have survived with restricted protein intake. Abnormal EEC, mental retardation, brain atrophy and hepatomegaly. 

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