In-vitro assays of workplace cocarcinogens were conducted. Compounds selected by NIOSH were evaluated for their ability to block metabolic cooperation between wild type and mutant Chinese-V-79- hamster cells. The concentrations of the compounds ranged from 0.01 to 25000 micrograms per milliliter. The inhibition of metabolic cooperation was evaluated by determining the number of surviving mutant cells. Mezerein (34807415), 12-o-tetradecanoylphorbol-13- acetate (544638), amobarbital (57432), butylated-hydroxytoluene (128370), phenobarbital (50066), butylated-hydroxyanisole (25013165), tryptophan (153946), and catechol (120809) inhibited metabolic cooperation between the wild type and mutant cells. Sodium-cyclamate (139059), 2,4-dinitrofluorobenzene (70348), benzoyl- peroxide (94360), phorbol (17673255), n-dodecane (112403), tert- butyl-hydroperoxide (75912), hydrogen-peroxide (7722841), and ethyl- phenylpropiolate (2216946) had no significant effect on metabolic cooperation. The overall response from the remaining compounds sodium-saccharin (128449), 1-phenyldodecane (123013), pyrogallol (87661), phenol (108952), and sucrose (57501) was either ambiguous or weakly positive. Tert-butyl-hydroperoxide and n-dodecane enhanced metabolic cooperation. The observed response of sucrose may represent changes in the osmolarity of the culture medium. Of the compounds tested, 15 have been accurately assessed for their ability to block metabolic cooperation.
Division of Biomedical and Behavioral Sciences, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio