Effect of exposure of foetal red cells to hydrogen peroxide

Foetal and adult red cells were exposed to H2O2 vapours using two different modes of exposure. There was a two-fold increase in adult (P < 0.05) and three-fold increase in foetal (P < 0.05) cells after 8 h of exposure 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, methaemoglobin was generated and there was a progressive increase in the formation 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 methaemoglobin formation between the adult and foetal red cells throughout the period of exposure (P < 0.05). The ability of both cell types to reduce methaemoglobin the presence of added substrates (glucose, inosine, adenosine, lactate and sorbitol) showed an enhanced reduction of methaemoglobin in adult red cells for lall the substrates added and a slower rate 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 all added substrates (P < 0.05). Our results showed that the foetal cells were more susceptible to oxidative stress than adult red cells.