Uptake of dieldrin,lindane, and DDT by isolated rat hepatocytes

Studies of the uptake of dieldrin, lindane, and DDT by isolated rat hepatocytes in Krebs-Henseleit salt solution containing 2.34% bovine serum albumin have shown that the partition equilibrium of these hydrophobic organochlorine compounds is established very rapidly between the hepatocytes and the extracellular medium by reversible uptake and release processes. In the hepatocyte suspension system, these compounds are in dynamic partition equilibrium between the hepatocytes and the Krebs-Henseleit salt solution, and also between the bovine serum albumin molecules and the solution. The respective rate constants for the uptake and release processes were 0.83 and 2.52 × 10^?2 sec^?1 in a 2-ml suspension containing 10⁶ cells. It has thus been demonstrated that the transport of hydrophobic organochlorine compounds between the hepatocytes and the extracellular medium is a much faster process than the metabolic transformation reaction in hepatocytes.