Effect of protein malnutrition on the neurobehavioural toxicity of styrene in young rats.

Neurotoxic effects of styrene on certain biochemical and behavioural indices were studied in young rats kept deficient in protein during the weaning period. Young rats fed a low-protein diet showed a significant decrease in the level of dopamine and an increase in frontocortical [3H]serotonin binding in comparison to the group of rats fed a normal protein diet. These rats also showed a significant increase in foot shock-induced aggressive behaviour, while no changes in amphetamine-induced locomotor activity, levels of norepinephrine and serotonin and binding of [3H]spiperone to striatal membrane were observed. On exposure to styrene, rats fed a normal protein diet showed a decrease in dopamine level and an increase in foot shock-induced aggressive behaviour only, with no significant change in other parameters, in comparison to the respective controls. It was, however, interesting to note that when rats fed a low-protein diet were exposed to styrene they showed a significant decrease in the levels of norepinephrine, dopamine and serotonin and an increase in the binding of [3H]spiperone and [3H]5-HT to striatal and frontocortical membranes, respectively. A significant increase in foot shock-induced aggressive behaviour and amphetamine-induced locomotor activity was also observed in this group of animals in comparison to those fed a low-protein diet. The biochemical and behavioural data indicate that protein deficiency makes young animals more vulnerable and it is an important predisposing factor in the neurobehavioural toxicity of styrene.