Influence of isotretinoin treatment on monoamines in different brain areas of male rats

ABSTRACT

Despite widespread use of isotretinoin for its anti-acne effects and its current evaluation in clinical trials as a cancer treatment, little is known about its effect on brain function and neuronal pathways in adult animals, particularly after oral administration which mimics the human route. Here, adult male rats were gavaged daily with olive oil and 1.5mg/kg/day isotretinoin for 4 weeks during which body weight was measured and changes in food intake and locomotor activity were observed. After decapitation, the concentrations of dopamine [DA], norepinephrine [NE], serotonin [5-HT] and 5-hydroxyindoleacetic acid [5-HIAA] were measured in different brain areas of rats after 2 and 4 weeks of repeated injection. The results show that, following isotretinoin administration body weight, food intake and locomotor activity were generally decreased. Treatment with isotretinoin produced marked increases in the concentrations of DA and 5-HIAA after 2 and 4 weeks and of NE after 4 weeks in the various brain regions examined. However, level of 5-HT was significantly decreased in most of the brain areas studied after 2 and 4 weeks following isotretinoin treatment. The results also show that all of these effects induced by isotretinoin treatment were tended to resolve within one week of drug cessation. It is possible to conclude that such alteration in monoamine systems could contribute to the isotretinoin induced increase in depression related behavior