Neurotoxicity of tetraphenylporphinesulfonate (TPPS4) and a hematoporphyrin derivative (Photosan) in organotypic cultures of chick embryonic dorsal root ganglia

The neurotoxic effect of tetraphenylporphinesulfonate (TPPS4) and a hematop orphyrin derivative (HPD, Photosan) has been studied in organotypic culture s of chick dorsal root ganglia maintained in a semi-solid culture medium. T he changes in two characteristics of neurite outgrowth, the mean radial len gth of neurites growing out from the ganglia and the area of neurite outgro wths, are used as parameters to evaluate the toxic effect. The porphyrins a re tested over the concentration range 10-160 mu g ml(-1). TPPS4 is slightl y more toxic than the HPD Photosan. The median inhibitory concentration (IC 50) for TPPS4 is 45-50 mu g ml(-1) and for the HPD Photosan 50-60 mu g ml(- 1), respectively. Nevertheless, the toxicity of the two drugs is relatively low compared to that of commonly used anticancer drugs, such as cisplatin or taxol. (C) 1998 Elsevier Science S.A. All rights reserved.