Immune lysis of hepatocytes in culture: accurate detection by aspartate aminotransferase release measurement.

Determination of the immune lysis of epithelial cells, especially of hepatocytes, in short term culture is dealt with inadequately because of the lack of accuracy inherent in most classical methods of measurement of cell lysis or because of the high spontaneous release of the lytic marker. We have studied different methods of detection of lysis of rat hepatocytes cultured for a short term (24-48 h) at a concentration of 10 000 cells/50 microliters. The determination of aspartate aminotransferase (ASAT) release, measured with a centrifugal analyser parallels lactate dehydrogenase (LDH) release and trypan blue dye staining which are indisputable markers of cell death, but ASAT release is a more sensitive determination. Surprisingly, 51chromium release (1.72%/h) is much higher than ASAT release (0.51%/h) for an experimental period of 24 h. In cell mediated cytotoxicity tests, the ASAT content of lymphocytes, in contrast to that of LDH, is much lower than that of hepatocytes and this makes determination of ASAT release a sensitive marker of cytotoxicity under these conditions.