EFFECTS OF ACUTE BENZENE EXPOSURE ON BRAIN ENKEPHALIN IMMUNOSTAINING AND DEGRADATION

Benzene is a widely used industrial neurotoxin. Its action in the brai n is not completely clear. Acute exposure to benzene in vivo reduces a minopeptidase activity in the hypothalamus and in the brain stem, and in vitro treatment with this toxicant generates a dose-related inhibit ion of this enzyme, notably in the brain stem. Enkephalin immunostaini ng shows a significant increase in substantia nigra, central gray (dor sal, lateral and pontine), and tegmental nuclei in acute in vivo benze ne-treated rats with respect to controls. In summary, this work shows an effect of benzene on the enkephalinergic system, which could be rel ated to the naloxone-reversible analgesia induced by the aromatic hydr ocarbon. (C) 1998 Elsevier Science Inc.