Tissue slices advantages

In vitro systems with varying levels of complexity have been used to study xenobiotic metabolism. These include purified proteins, subcellular fractions/cell lysates, intact whole cells, tissue slices and whole organ culture. Advantages and disadvantages of the approaches are summarized below. 

In the past decades, there has been a large increase in the development and use of in vitro models, not only because of the demand of animal welkre groups to reduce the use of laboratory animals, but also because of a number of scientific and financial advantages. Especially in the case of small laboratory animals, a number of different models have become available for biotransformation and toxicity studies, e,g, perfused organs, tissue slices, isolated cells (e,g, hepatocytes), cellular fractions (e.g. microsomes), and purified enzymes. For a number of reasons (see below) isolated hepatocytes have become one of the most popular in vitro models for such studies. 

These can be conventional cross-sectional slices up to 0.5 mm thick, or small cubes (0.1-0.5 mm on each plane) or pyramids of brain tissue. The main advantage of using slices is that, either by crudely passing currents across them or, in some cases, stimulating a... 

Liver slices have all the advantages of primary hepatocytes. In addition, the complete hepatic architecture is maintained so that sequential pathways that potentially involve several cells can also be studied. The limitation with liver slices is that they cannot be stored for long and not much work has been done to validate their use in enzyme induction. It is also very important to study a range of samples from different livers to obtain representative results. Human liver samples should be characterized as fully as possible with regard to gender, age, medical and drug history, and metabolic activity. Liver tissue samples should be obtained as soon as possible after surgery and stored rapidly at -80°C. 

The tissue chopper, on the other hand, has the advantage of low cost and faster slicing. The available commercial tissue choppers include the Tissue Sheer from Stoelting (Wood Dale, IL) and Mcllwain Tissue Chopper (Mickle Laboratories Engineering, Gromshall, Surrey, UK), Slicing is improved if the subarachnoid membrane is removed. 

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