Institut für Rechtsmedizin, Johannes Gutenberg Universität Mainz, Am Pulverturm 3, 55131 Mainz, Germany
* Institut für Rechtsmedizin und Verkehrsmedizin, Ruprecht-Karls-Universität, Vosstr. 2, 69115 Heidelberg, Germany

In the present experimental approach the uptake of ³H-cocaine/benzoylecgonine (BZE) by keratinocytes was compared to that by melanocytes. The cultured cells were exposed to various ³H-cocaine/BZE concentrations and incubation periods up to 168 hours. All test series were run in triplicate.

In both cell types the uptake of ³H-cocaine/BZE was dependent on the drug concentration in the medium. After 72 hours an increased uptake of ³H-cocaine/BZE was already found, ³H-cocaine/BZE activity in 1 x 10⁶ melanocytes was twice as much as in 1 x 10⁶ keratinocytes. Following the time course over 168 hours, the uptake by melanocytes further increased leading to concentrations 5 times higher than in the keratinocytes.

These preliminary findings are discussed with respect to drug accumulation in the melanosomes due to melanin associated drug molecules.