Effects of halothane on the intracellular Ca²⁺ concentration of isolated guinea pig hepatocytes

The effects of halothane on the intracellular Ca²⁺ concentration ([Ca²⁺](i)) of isolated guinea pig hepatocytes were investigated. When hepatocytes were incubated in Hank's solution containing Ca²⁺, trypan blue uptake which indicates death of cell was 13.5 ± 3.41%, and [Ca²⁺](i) was 158 ± 73.5 nM in control. By halothane exposure, both trypan blue uptake and [Ca²⁺](i) were increased in concentration dependent fashion (Fig. 2, 3). When hepatocytes were incubated in Hank's solution excluded Ca²⁺, trypan blue uptake was 31.2 ± 6.40%, and [Ca²⁺](i) was 249 ± 27.5 nM in control. By halothane exposure, trypan blue uptake was increased in concentration dependent fashion, while [Ca²⁺](i) was decreased (Fig. 4, 5). From these results, the increase of trypan blue uptake in experiment 1 and 2 indicate the hepatotoxicity of halothane with or without Ca²⁺ in medium. The increase of [Ca²⁺](i) of hepatocytes in physiological condition indicate the direct injury of halothane to hepatocyte cell membrane.