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

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

Effect of atropine on acetylcholinesterase and monoamine oxidase activities in discrete brain regions of albino rat

The changes in AChE and MAO activities were studied in nine brain regions of albino rat following daily i.p. injection of two separate doses of atropline sulfate [0.8 or 1.6 mg/100 g body wt] for six days. Injection of either of the two doses provoked a general decrease of AChE in most of the brain areas studied. The amount of decrease was not the same at the different time intervals investigated. This decrease may be due to an interruption of brain cholinergic synapses which form a part of inhibitory mechanism controlling the activity of cholinergic neurones. The effect of atropine sulfate on MAO activity is variable from region to region which may be due to both the release of enzyme from the mitochondrial membrane and changes in its catalytic properties

Effect of sodium barbitone on acetylcholinesterase and monoamine oxidase activities in discrete brain regions of albino rat

The effect of i.p. injection of two separate doses of sodium barbitone [10 or 20 mg/100 g body wt.] on the AChE and MAO activities was studied in nine brain regions of albino rat after one, 2, 3, 4, 5 and 6 days of repeated injection. Injection of 10 mg sod. barbitone/100 g body wt. provoked a general increase in AChE activity in most of the brain parts, however 20 mg sod. barbitone/100 g body wt induced a decrease rather than an increase in the AChE activity of the different brain areas during the whole experimental period. Administration of either of the two doses of sodium barbitone provoked a general increase of MAO activity in the different brain regions and the amount of increase was not the same at the different time intervals investigated. It is possible to conclude that the changes in the activity of the catabolic enzymes [AChE and MAO] in the different brain regions of rat following drug treatment may be associated with the rapid reactions in a general regulatory system against chemical stress