Involvement of oxidative stress in the regulation of NPY/CART-mediated appetite control in amphetamine-treated rats.

Amphetamine (AMPH) treatment can suppress appetite and increase oxidative stress in the brain. AMPH-induced appetite suppression is associated with the regulation of neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART) in the hypothalamus. The present study explored whether antioxidants, including glutathione S-transferase (GST) and glutathione peroxidase (GP), were involved in this NPY/CART-mediated appetite control. Rats were treated daily with AMPH for four days. Changes in food intake and expression levels of hypothalamic NPY, CART, GST, and GP were examined and compared. Results showed that, in AMPH-treated rats, (1) food intake and NPY expression decreased, while CART, GST, and GP expression increased; (2) NPY knockdown in the brain enhanced the decrease in NPY and the increases in CART, GST, and GP expression; and (3) central inhibition of reactive oxygen species production decreased GST and GP and modulated AMPH anorexia and the expression levels of NPY and CART. The present results suggest that oxidative stress in the brain participates in regulating NPY/CART-mediated appetite control in AMPH-treated rats. These results may advance the knowledge regarding the molecular mechanism of AMPH-evoked or NPY/CART-mediated appetite suppression.