Aspartate Aminotransferase Isoenzymes in Human Serum in Various Liver Diseases

Abstract

The isoenzymes of aspartate aminotransferase were studied in serum in various liver diseases by means of a simple chromatographic technique. The percent activity of AAT II was decreased to normal values in acute hepatitis; on the contrary, it was increased in acute liver atrophy. This suggests that the mitochondria are more severely damaged in the latter disease than in the former.

Immunological determination of serum m-AST activity in patients with acute myocardial infarction.

“…In our study the mean value of the individual maximal m-AST/t-AST was 30 2 + 1F7 per cent (12 to 64) and this value is significantly greater than those in the patients with liver disease previously reported (Farmer et al, 1970;Ideo et al, 1971). In the present study, the mean ratio of m-AST/t-AST in 35 patients with liver disease was 12-2 + 1-9 per cent and was similar to the previous reported results (Fleisher and Wakim, 1961).…”

“…; AST) consists of two isoenzymes, one associated with the cytoplasmic fraction (s-AST) and the other with mitochondria (m-AST) (Fleisher et al, 1960;Borst and Peeters, 1961;Boyd, 1961;MassarratandLang, 1965). Since AST is mainly contained in striated muscle, myocardium, and liver, its serum activity has been found to rise in diseases of these organs (Schmidt et al, 1967;Farmer et al, 1970;Ideo et al, 1971). Though the ratio of serum m-AST activity to total serum AST (t-AST) activity has been reported to represent the severity of cellular damage in liver disease (Schmidt and Schmidt, 1961;Ideo et al, 1972), the clinical significance in myocardial infarction of m-AST and the ratio m-AST/t-AST remains unsettled, probably because the previous methods for the determination of m-AST using electrophoresis or column chromatography were inadequate insensitivity as well as quantitatively (Fleisher et al, 1960;Boyd, 1961;Bodansky et al, 1966;Id6o et al, 1971).…”

The Proportion of Mitochondrial Isoenzyme of Aspartate Aminotransferase Is Not Elevated in Reye's Syndrome

“…The mean % of mitochondrial isoenzyme for the normal group in the previous report is 25%, a value near the maximum that has ever been reported (7,9,18) and higher than we detected in any individual in any group. This high mean % of mitochondrial ---activity for the normal group suggests that the chromatographic techniaue used in the ~revious studv.…”

“…To determine the activity of the mitochondrial and cytosolic isoenzymes in a serum sample, we separated the isoenzymes by column chromatography using DEAE-Sephadex-A50 (Pharmacia), a resin with both molecular sieving and ion exchange properties. Previous studies had been criticized for prolonged dialysis before chromatography, which might lead to selective loss of mitochondrial activity (9). For the conditions utilized in this study, we determined that prior dialysis was not necessary, and dialysis was omitted.…”

Single-Center Experience With Liver Transplant Using Donors With Very High Transaminase Levels

“…Clearance depends on the rate at which the enzymes are released from cells and the rate at which they are taken up by sinusoidal-lining cells. 17 Therefore, the serum level observed in a single assay does not necessarily reflect the total amount released or the extent of ischemic damage. The half-life of AST in the circulation is 17 ± 5 hours, whereas that of ALT is 47 ± 10 hours.…”