Effect of Pyrogallol on the Catecholamine Contents of Cortex, Diencephalon, Mesencephalon, Rhombencephalon and Cerebellum of Mouse and Rat

Abstract

In mice and rats, the catecholamine contents and distribution in encephalic structures are quite similar. At the dose of 10 mg/kg P provokes: In mouse, significant increase of catecholamines in cerebellum cortex > rhombencephalon after 10 minutes, with normalization after 20 minutes. In the rat, significant increase of catecholamines after 20 minutes in rhombencephalon > cortex > mesencephalon > cerebellum; after 40 minutes in diencephalon also; after 120 minutes it is significant only in rhombencephalon. The increase of catecholamines is unrelated to the normal concentration of each tissue. This increase is very large in mouse cerebellum. At dose of 200 mg/kg intraperitoneally,P interferes with the fluorometric reaction; however, it significantly increases catecholamines in rat mesencephalon and cerebellum. The observed effects are ascribed to catechol-oxy-methyl transferase (COMT) inhibition by P and suggest differences in the encephalic enzymatic contents of mouse and rat.