ABSTRACT
Screening test for G-6-PD was carried out on 100 subjects in Calabar using the methaemoglobin reduction test of Brewar et al, [1978]. Twenty percent of the subjects were deficient for G-6-PD, while 80% were normal. Of the 27 female subjects screened, none was deficient for the enzyme. Out of the 73 males, 53 were normal, while 20 were deficient. The difference between deficient male subjects and female was statistically significant [P<0.05]. Different concentrations of potassium cyanide [KCN] were incubated with the 80 blood samples that were normal for G-6-PD for 30 min at 37°C and G-6-PD screening was reported. It was observed that 0.15 mml/L KCN had a significant inhibitory effect on erythrocyte G-6-PD activity in vitro with apparent inhibitory affect of the cyanide indicated at other concentrations of the salt. The inhibition effect of cyanide seen in vitro may inversely represent an in vivo inhibitory effect, therefore there is need to modify the processing method of one of our regular food stuffs like cassava, bean and corn to completely remove cyanide and thereby to prevent possible inhibition of G-6-PD activity. Further direct study on the in vivo effect of the cyanide on G-6-PD activity is proposed