l-arginine minimizes immunosuppression and prothrombin time and enhances the genotoxicity of 5-fluorouracil in rats.

Objective: The aim of this study was to evaluate the effect of low doses of l-arginine supplementation on hemogram, integrity of DNA and spleen, inflammatory infiltrate in the jejunum, and in the coagulogram of rats submitted to 5-fluorouracil (5-FU) chemotherapy.

Methods: Thirty-two Wistar rats were fed commercial feed and water ad libitum and grouped into four (eight rats per group): The control group was given a 0.9% physiologic solution to simulate the application of 5-FU in the other groups; the G group was given a dose of 5-FU; the G and G groups were given a dose of 5-FU and supplemented with 50 and 100 mg l-arginine/d added in the drinking water ad libitum.