Glutathione-S transferase activity in cultured human hepatocytes

Glutathione S-transferase (GST) activity was measured in human hepatocytes just after isolation and during culture in various media. Individual variations in enzyme activity, using 1-chloro-2,4-dinitrobenzene as substrate, were observed for freshly isolated human hepatocytes. When the hepatocytes were cultured, GST activity decreased dramatically during the first two days, to be stabilized around 30% of the initial value. Even factors known to favour maintenance of liver functions in vitro, such as nicotinamide and dimethylsulfoxide (DMSO), did not prevent this decline. In contrast to rat hepatocytes, no increase of GST activity was observed following the early decrease.