LEAKAGE OF MITOCHONDRIAL AND CYTOSOLIC GOT IN ISOLATED RAT HEPATOCYTES EXPOSED TO HALOTHANE - AN IMMUNOHISTOCHEMICAL STUDY

The leakage of mitochondrial (m-) and cytosolic (s-) aspartate aminotr ansferases (glutamic-oxaloacetic transaminase: GOT) from isolated hepa tocytes exposed to halothane was investigated immunohistochemically. I n control isolated hepatocytes, a large number of cells were immunopos itive (m-GOT, 85%; S-GOT, 98.5%) at various intensities. Reaction prod ucts of m-GOT-immunohistochemistry (m-GOT-I) were seen exclusively in mitochondria, while those of s-GOT (s-GOT-I) were seen in the cytoplas m. When treated with low concentrations of halothane (up to 0.75%), th e number of strongly m-GOT-I-immunopositive cells was reduced to half, while that of s-GOT-I showed no noticeable change. The number of m-GO T-I-immunonegative cells showed a negligible increase, while that of s -GOT-I increased gradually. At higher concentrations of halothane (1% or more), strongly immunopositive cells in both m- and s-GOT-I almost disappeared, while immunonegative cell numbers predominantly increased . This study showed that the isolated hepatocyte system was not homoge neous with regard to the quantity of GOT isozymes, and that halothane could induce the leakage of these isozymes from hepatocytes, along wit h inducing ultrastructural abnormalities, even at the lowest concentra tion used (0.5%). Furthermore, the data appear to indicate that the se nsitivity of isolated hepatocytes to halothane is dependent on the nat ure of the hepatocyte itself and on the nature of both types of GOT is ozymes.