Liver morphology and enzyme release: further studies in the isolated perfused rat liver

An improved technique for isolated perfusion of rat livers and an evaluation of perfusates

“…Hepatic function was more stable as judged by constant enzyme levels and bile production. The leakage of hepatocellular enzymes in these perfusions were also considerably less than in other reports using cell-free or bloodcontaining perfusates [26,27]. These findings may be related to a toxic effect of bovine albumin on the rat liver.…”

Clinical Enzymology

“…The release rates from the livers of fasted rats are between 2.5-fold and 5-fold higher than from fed rats, though oxygen consumption is similar in both conditions, and extracellular glucose levels are very well maintained by the glycogen-depleted livers. The same is true for the lactate/pyruvate and the ATP/ADP ratios in the liver [36] (table 2). The histological appearance of the liver tissue is likewise virtually normal.…”

“…When increased permeability has been produced previously by a variety of causes, enzyme leakage from the perfused liver was considerably aggravated (fig.5) [36]. In comparing the different types of injury not only quantitative variations can be noticed, but there are also conspicuous qualitative differences of the enzyme patterns in the perfusion medium.…”

“…This occurs immediately with mitochondrial (and acinocentral) GLDH, later with partly mitochondrial GOT, and even more delayed with cytosolic GPT and LDH. Though oxygen consumption is twice as high at 37°C as it is at 23°C, the relative oxygen shortage can clearly be read from the continually increasing lactate/pyruvate ratio [36]. Fig.3 shows that temporary absolute lack of oxygen also leads to a steep rise in enzyme activities in the perfusion medium, which persists (with the exception of GLDH) after the restitution of oxygen supply.…”

“…In comparing the different types of injury not only quantitative variations can be noticed, but there are also conspicuous qualitative differences of the enzyme patterns in the perfusion medium. These can be attributed on the one hand to different involvement of subcellular structures with the different toxic substances, thus proving again the importance of the intracellular localization of enzymes ( fig.6) [36]. On the other hand, the heterogeneity of enzyme distribution throughout the hepatic lobule affects the release rates in proportion to the cell damage in the periphery or in the central area of the lobule ( fig.7).…”