Thiamine deficiency induced by polychlorinated biphenyls (PCB) and dichlorodiphenyltrichloroethane (DDT) administration to rats.

To clarify the effect of polychlorinated biphenyls (PCB), and dichlorodiphenyltrichloroethane (DDT) and other organochloride compounds on thiamine metabolism, rats were separated into six groups and placed on different admixed diets. Group 1 was fed a normal diet; group 2, a PCB-supplemented diet; group 3, a DDT-supplemented diet; group 4, a benzenehexachloride-supplemented (BHC) diet. After 50 days of these dietary regimens all animals were sacrificed and various studies were done on the excised tissues. In PCB-treated rats, thiamine levels in blood, liver and sciatic nerve decreased, transketolase activity in erythrocytes and liver decreased and TPP effect in erythrocytes and liver increased. In DDT-treated rats, thiamine levels in blood, brain and liver decreased, transketolase activity in brain and liver decreased and TPP effect in brain and liver increased. In other groups, no significant changes were observed regarding thiamine metabolism. Our findings provide direct evidence that changes occur in thiamine metabolism in PCB- and DDT-poisoned rats.