Abstract: AIM:To understand the toxic effect of primaquine and aniline on the formation of
methemoglobin (MHb) and proliferation of reticulocyte (ret) . METHODS:Two groups of male
Sprague- Dawley rats were each given intraperitoneally with 3% aniline peanut oil solution at
a single dose of 1 ml/ kg and intragastrically with primaquine 40 mg/ kg per day for 7 days, respectively. Another two groups receiving corresponding solvents were served as controls. Blood MHb level and retcountwere determined at 2h,24h,48 h and 72h after medication for aniline and every day for primaquine from the day of the administration of the second dose of drug till the 5th day after treatment, and then every other day till the 15th day. RESULTS: The mean percentage concentration of MHb and ret count in aniline group rats was significantly higher than those of the controls at 2h and 24 h after aniline administration, indicating that the rats in the aniline group presented acute in travascular hemolytic reaction. No remarkabale changes were found in the mean percentage concentration of MHb in primaquine group rats after medication, while the mean ret count was significantly lower during and after treatment than those before medication. CONCLUSION: In rats, primaquine could inhibit the proliferation of reticulocytes, but did not induce any acute intravascular hemolytic reaction similar to those seen in aniline group rats.

Key words: A niline, primaquine, m ethem oglobin, reticulocyte, hemolysis, rat, glucose- 6 - phosphate dehydrogenase