Inhibition of intercellular communication in Chinese hamster V79 cells by fractionated asphalt fume condensates.
Toraason-M; Bohrman-JS; Elmore-E; Wyatt-G; McGregor-D; Willington-SE; Zajac-W
J Toxicol Environ Health 1991 Sep; 34(1):95-102
A metabolic cooperation assay was carried out in Chinese-hamster V79 cells to study the effects of asphalt (8052424) fume condensate and five of its fractions on intercellular communication. Fumes were generated from a type III asphalt by heating it to 316 degrees-C. The parent fume and five fractions were obtained by high performance liquid chromatography. Fractions were dried and reconstituted in acetone and cyclohexane solvent. V79 lines sensitive and resistant to 6-thioguanine (6TG) were used for the metabolic cooperation assay to measure intercellular communication as transfer of a toxic metabolite of 6TG from sensitive cells (capable of forming the metabolite) to resistant cells. Asphalt fume condensates were added to plated cells, and 6TG was added 15 minutes later. Medium without fume condensates but containing 6TG was substituted after 3 days. Survival of sensitive and resistant colonies was quantitated after another 3 to 4 days. Cytotoxicity of fume condensates was also measured. Gas chromatography with mass spectrometry was used to characterize chemical classes within each condensate fraction. Four of the fractions were cytotoxic in the range 15 to 20 micrograms per milliliter (microg/ml). The other fraction and the parent condensate had limited solubility. Intercellular communication was inhibited dose dependently by the parent asphalt fume condensate and the four soluble fractions. The most potent fraction (containing alkylated phenols and alkylated ketones) inhibited communication at 2.5microg/ml. The other inhibitory fractions were active at 10microg/ml or less, and the insoluble fraction was only inhibitory at the highest concentration (50.0microg/ml). The authors conclude that fractionated asphalt fume condensates significantly inhibit intercellular communication in V79 cells in a manner similar to cytotoxic activities.
NIOSH-Author; Laboratory-animals; In-vitro-studies; Carcinogens; Cell-cultures; Asphalt-fumes; Dose-response; Biological-effects; Cytotoxic-effects; Cell-alteration; Cellular-function
Journal of Toxicology and Environmental Health