Effects of aromatic nitro and amino compounds on the osmotic fragility of red cells

Abstract

Using the Coil Planet Centrifuge system, effects of single and repeated subcutaneous injections of p-nitrochlorobenzene [PNCB], aniline [AN] and phenylhydrazine [PH] on the osmotic fragility of red cell membrane in rabbits were studied. Methemoglobin [MHb] levels and appearance of Heinz bodies were also determined. In the single injection experiment, the osmotic fragility was increased immediately after the subcutaneous injections of PNCB [50 mg/kg, 100 mg/kg and 200 mg/kg], AN [50 mg/kg, 250 mg/kg and 500 mg/kg] and PH [25 mg/kg and 45 mg/kg]. The increased MHb levels were observed first, and secondly the maximum changes of the osmotic fragility and appearance of Heinz bodies were observed nearly simultaneouly after the injections of these three compounds. In the repeated injection experiment, hemolysis starting point was shifted toward higher osmotic pressure immediately after the injections of PNCB [5 mg/kg/day and 10 mg/kg/day], AN [20 mg/kg/day and 30 mg/kg/day] and PH [1 mg/kg/day and 3 mg/kg/day], while it was shifted toward lower osmotic pressure after the last doses of PNCB and PH. Hemolysis ending point was shifted toward higher osmotic pressure after the injections of PNCB [10 mg/kg/day] and AN, while it was shifted toward lower osmotic pressure after the injections of PNCB [5 mg/kg/day] and PH. The injection of PNCB induced continuously the increased MHb levels and appearance of Heinz bodies. The injection of PH induced the continuous appearance of Heinz bodies and the transiently increased MHb levels. Although the injection of AN induced the transiently increased MHb levels, there were no appearance of Heinz bodies. These findings show that the early and continuous changes in red cell membrane induced by these three compounds were able to be detected by the use of the Coil Planet Centrifuge system. The changes in red cell membrane induced by single and repeated injections of PH were able to be detected even when the increased MHb levels were not detected. Furthermore, the changes induced by the repeated injection of AN were able to be detected even when the increased MHb levels and the appearance of Heinz bodies were not detected. Thus, it seems likely that the Coil Planet Centrifuge method is useful to examine workers exposed to aromatic nitro and amino compounds.