Enzyme Preparation for Optimal Extracorporeal Enzymatic Detoxification

Abstract

The clinical results of liver transplantation and extracorporeal liver perfusion in fulminant hepatic failure indicate that a whole liver is the best source for enzymatic detoxification. However, a human, monkey, or baboon liver are not always available for these therapeutic methods and at present cannot be preserved over long periods of time. The development of the lipophilic hollow fiber technique has made it possible to remove fat- soluble toxins from the blood and metabolize them by using extracted liver enzymes without complicated processes and immunologic reactions [1, 2; A. Freimann-Kersebaum, G. Brunner, unpublished observations]. Cellular or subcellular sources can be utilized as liver enzymes, and there are many differences in preparation, handling, and thus cost among them. In this study liver homogenate, isolated hepatocytes, microsomes or cytosol, and partially purified enzymes were investigated for the three detoxifying enzymes cytochrome P-450 hydroxylase (P-450-Hx), UDP-glucuronyltransferase (UDPGTase), and glutathione S-transferase (GSTase) with regard to total enzyme yield, efficacy, cost, storage, and stability.