Effects of the long-term administration of methamphetamine on body weight, food intake, blood biochemistry and estrous cycle in rats

We have a big problem with the abuse of amphetamine and its close relative, methamphetamine (MAP) in Japan. As an animal model of people who abuse MAP, male and female rats were treated with MAP (0.1-10.0 mg/kg/day) for a long time. The results obtained in the present study were as follows. 1. Body weights in MAP-treated groups showed a dose-dependent decrease with loss of food intake. 2. Food intake in rats treated with MAP decreased, compared with the control, but when treatment with MAP was discontinued, food intake increased dramatically. 3. In a blood biochemistry assay, the turnover of protein and lipid was suppressed in rats after MAP. 4. The administration of MAP appeared to disturb the estrous cycle in female rats.