DIFFERENT ACTIVITY OF ADENYLYL-CYCLASE IN PREFRONTAL CORTEX IN 3 RAT STRAINS - THE EFFECT OF AMPHETAMINE

Since the literature data do not provide enough information on the eff ects of amphetamine on the prefrontal cortex and since many controvers ial findings were reported in various rat strains we decided to compar e adenylyl cyclase activity in the prefrontal cortex in various rat st rains and test the effects of chronic amphetamine treatment (for 14 da ys) on the activity of this enzyme, Basal adenylyl cyclase activity wa s lower in Wistar rats than in Sprague-Dawley and Lewis rat strains. A mphetamine treatment produced in Wistar rats a substantial decrease in basal adenylyl cyclase activity. In Sprague-Dawley rats, me observed the highest enzyme activity which was slightly reduced after amphetami ne treatment, In Lewis rats which had basal activity close to the acti vity of Wistar rats, amphetamine produced an increase in enzyme activi ty. The total adenylyl cyclase activity, estimated ill the presence of forskolin, was the lowest in Wistar rats. The highest stimulation was observed in Lewis rats, Amphetamine treatment caused a very significa nt inhibition of total adenylyl activity in Wistar rats and a smaller inhibition in Sprague-Dawley rats. However, in Lewis rats amphetamine treatment increased the dose-response curve of forskolin stimulation, These results show that Lewis rats, compared to the other two strains, develop not only quantitatively but also qualitatively different resp onses.