Effects of Some Xenobiotics on the Disposition of Brain Serotonin and Catecholamine in Rats

抄録

Exposure to some xenobiotics (pentobarbital, 3-tert-butyl-4-methoxyphenoI (BHA), chloretone (acetone chloroform), 1, 1-bis-(p-chlorophenyl)-2, 2, 2-trichloroethane (DDT) and poly chlorinated biphenyls (PCB)) for a 5 hr period increased the concentrations of brain serotonin and 5-hydroxyindole acetic acid (5HIAA). The decrease in the brain serotonin level elicited by p-chlorophenylalanine (PCPA), an inhibitor of serotonin synthesis, was prevented by the concomitant administration of chloretone. The administration of both chloretone and pargyline (an inhibitor of monoamine oxidase) caused significant elevation of the brain 5HIAA level as compared with that in a pargyline control, however, the concentration of brain serotonin was not different between pargyline alone and chloretone plus pargyline. These results show that the increase in the brain serotonin level caused by chloretone is not due to acceleration of brain serotonin synthesis, but to retardation of the degradation of brain serotonin, and the increase in brain 5HIAA caused by chloretone may be due to the reduced removal of SHI A A from the brain. Chloretone plus pargyline caused significant elevation of hypothalamus catecholamines, as compared to in the pargyline control, so the catecholamine turnover rates may be accelerated by the administration of chloretone.