The antipsychotic drug sulpiride induces insulin intolerance but does not affect body weight in adult male mice

Research studies have shown that chronic administration of some antipsychotic drugs induces obesity in female but not in male. To explore the mechanisms involved in this effect, we administrated the dopamine antagonist sulpiride (40 mg/kg) or vehicle intraperitoneally to adult male mice during 45 days and then the glucose tolerance and serum levels of insulin, serum, and testicular testosterone and prolactin, and blood estrogen levels were evaluated. Chronic sulpiride administration did not affect body weight. However, prolactin levels and the area under the glucose and insulin curves were significantly elevated. Sulpiride significantly decreased testosterone and increased estrogen levels (p < 0.05). After prolonged administration, sulpiride did not affect body weight, so this lack of effect may be related to the impairment of insulin sensitivity which prevents body weight gain and deals with other effects of sulpiride that cause adiposity promotion such as hyperprolactinemia. Future studies must evaluate other neurotransmitters involved in food intake regulation such as histamine and serotonin.