A new erythrocyte fragility test: a simple procedure utilizing stirring.

In this study, a new simple method to measure erythrocyte fragility with stirring of diluted blood (stirring method) was introduced and evaluated with anemic rats given beta-acetylphenylhydrazine (APHZ) or clofibrate. APHZ at a dose of 40 mg/kg caused significant decreases in hemoglobin and hematocrit 24 hr after administration. However, the marked elevation of erythrocyte fragility was already detectable after 6 hr by our stirring method. At a dose of 10 mg/kg APHZ, although no significant changes in the erythrocytic parameters were observed throughout the experimental period (72 hr), the blood stirring method revealed a marked elevation of erythrocyte fragility 6 hr after administration. Similarly with clofibrate, no changes in erythrocytic parameters were noted following 100 mg/kg or 300 mg/kg administration, but the enhanced fragility was evident with the stirring method. Thus, using our approach, the erythrocyte fragility could be detected at an earlier stage and with greater sensitivity than by decreases in erythrocytic parameters. The results suggest that the stirring method will prove to be useful for detecting erythrocyte fragility in safety studies.