EFFECT OF EXPOSURE OF FETAL RED-CELLS TO HYDROGEN-PEROXIDE

Foetal and adult red cells were exposed to H2O2 vapours using two diff erent modes of exposure. There was a two-fold increase in adult (P<0.0 5) and three-fold increase in foetal (P<0.05) cells after 8 h of expos ure to H2O2 using the Cohen and Hochstein technique. When the H2O2 was generated in situ by the glucose-glucose oxidase technique, there was also an increase in formation of methaemoglobin in both cell types (P <0.05). In the presence of sodium azide in both cell types, methaemogl obin was generated and there was a progressive increase in the formati on of methaemoglobin with time of exposure in both cell types (P<0.05) using either the Cohen and Hochstein procedure or the glucose-glucose oxidase procedure. There was significant difference in the methaemogl obin formation between the adult and foetal red cells throughout the p eriod of exposure (P<0.05). The ability of both cell types to reduce m ethaemoglobin the presence of added substrates (glucose, inosine, aden osine, lactate and sorbitol) showed an enhanced reduction of methaemog lobin in adult red cells for lall the substrates added and a slower ra te of reduction of methaemoglobin to functional haemoglobin in foetal cells. There was significant difference in the percentage drop in the methaemoglobin formation between the adult and foetal red cells with a ll added substrates (P<0.05). Our results showed that the foetal cells were more susceptible to oxidative stress than adult red cells.