kaolinite and Neuroblastoma

To assess the cytotoxicity of four clays containing an aluminum silicate--montmorillonite, bentonite, kaolinite and erionite--we used human umbilical vein endothelial, N1E-115 neuroblastoma, and ROC-1 oligodendroglial cells. Morphological examination, lactate dehydrogenase release and fatty acid release were used as indices of trauma. The clays were added in suspension to the cell cultures at concentrations of 0.1, 0.03 and 0.01 mg/ml of medium and the cells were incubated for 1, 6 and 24 h. The clays did not lyse ROC-1 and N1E-115 cells and did not cause a dose-dependent increase in fatty acid levels at 24 h. There were no significant increases in lactate dehydrogenase activity in N1E-115 neuroblastoma or ROC-1 oligodendroglial cells. In human umbilical vein endothelial cells, montmorillonite, kaolinite and bentonite caused a dose-dependent increase in fatty acids at 24 h. All three clays caused cell lysis. We postulate that the cytotoxicity of the clays containing an aluminum silicate towards endothelial cells may disrupt the blood-brain barrier in the affected areas, allowing the entry of the clay particle into the brain. Aluminum silicate clays caused a dose-dependent release of fatty acids in human umbilical vein endothelial cells. The clays also caused lysis of these cells. ROC-1 oligodendroglia and N1E-115 neuroblastoma cells were not lysed by the clays, suggesting that this is not a general phenomenon.

Topics: Aluminum Silicates; Bentonite; Cell Survival; Cells, Cultured; Endothelium, Vascular; Fatty Acids; Humans; Kaolin; L-Lactate Dehydrogenase; Neuroblastoma; Neurotoxins; Oligodendroglia; Tumor Cells, Cultured; Umbilical Veins; Zeolites

The recently reported presence of alumino-silicates in the core of Alzheimer's senile plaques raises a number of questions concerning the little studied area of interactions between solid particles and neuronal tissue. In this preliminary study we report that contact between crystalline alumino-silicates and cultured neuroblastoma cells selectively caused a rapid increase in membrane electrical conductance and loss of excitable activity. Severe morphological deterioration was subsequently evident within 30 min of exposure. Similar effects were induced by a magnesium silicate mineral but not by aluminum hydroxides or by silicon in the form of quartz. Homogeneously charged synthetic particles did not induce changes in electrical function of the cells. These results suggest that a layout incorporating both negative and positive charges, as can be found on the broken edges of platy clay metallo-silicates, and the non-isodiametrical geometry of the particles may be necessary for the acute neurotoxic interaction observed.

Topics: Action Potentials; Aluminum; Aluminum Hydroxide; Animals; Cell Line; Cell Membrane; Cell Survival; Clone Cells; Electrophysiology; Kaolin; Mice; Microscopy, Electron, Scanning; Neuroblastoma

Topics: Animals; Antigen-Antibody Reactions; Astrocytoma; Avian Sarcoma Viruses; Brain Neoplasms; Cell Transformation, Neoplastic; Cerebral Ventricles; Dogs; Ependymoma; Genetics, Microbial; Glioma; Histiocytes; Hydrocephalus; Kaolin; Microscopy, Electron; Neuroblastoma; Sarcoma, Avian; Sarcoma, Experimental; Staining and Labeling