Distribution of aromatase activity in cultured neurons and glia cells.

Aromatase plays a crucial role in the mechanism of action of testosterone in the central nervous system. Nevertheless, the exact cellular localization of this enzymatic complex within the different cell populations of the brain is still uncertain. In the experiments described here the presence of aromatase (assayed by the tritiated water method) has been evaluated in the two main cellular components of the brain: neurons and glia. Neurons, mixed glial cells, type 1 astrocytes, were obtained in cultures; oligodendrocytes were prepared by gradient ultracentrifugation. The results indicate that, among the different cells tested, only neurons possess a significant degree of aromatase activity, while the enzymatic activity is extremely low in mixed glial cell and in astrocyte preparations. Oligodendrocytes seem to be completely inactive in this respect.