High-fat diet aggravates islet beta-cell toxicity in mice treated with clozapine.

Background : Clozapine, an atypical antipsychotic drug, induces derangements in glucose homeostasis in certain patients. This study investigated the mechanisms of clozapine-induced beta-cell toxicity. Methods : Fifty-two healthy C57BL/6 male mice were randomized into 4 groups to study the effects of clozapine (group C, D) and a high-fat diet (group B, D). Three mice from each group were randomly selected to determine the amount of food intake on days 8-10, and their pancreases were removed for histological examination on day 11. The remaining 10 mice in each group were sacrificed at the 8th week to measure pancreatic insulin content (PIC). Results : Mice given clozapine for 8 weeks demonstrated trends of lower PIC. The histological examination of the pancreases retrieved on day 11 already revealed apoptotic changes and suppression of cell proliferation. Although mice fed high-fat chow gained weight, mice given both clozapine and a highfat diet showed less weight gain and more severe histological deterioration, and had the lowest PIC levels of the 4 groups. Conclusion : Pancreatic beta-cell apoptosis, suppression of cell proliferation, and trends of reduction in pancreatic insulin content were observed in mice taking clozapine. The findings of clozapine induced beta-cell toxicity were further aggravated when mice were concomitantly fed a high-fat diet.