Concentration-Dependent Effect of Ivermectin on Adenosine Triphosphatase (Atpase) Activities in Human Erythrocytes

Ivermectin remains the drug of choice for Onchocerciasis treatment and previous studies have documented an inhibition of Adenosine Triphosphatase (ATPases) activities in adult Onchocerca volvulus. The study is aimed at examining the effects of Ivermectin on ATPase activities of human erythrocytes. Sixty (60) subjects, (30 males and 30 females) residing in Enugu metropolis, were recruited for the study. Venous blood samples (3 mL) were collected from each subject from where erythrocyte ghosts were prepared. Erythrocyte ghosts were prepared via hypotonic lysis, using ice-cold sodium phosphate at pH 7.4. Total ATPase, magnesium (Mg2+) and Calcuim (Ca2+) ATPase activities were assayed using standard spectrophotometric methods, before and after Ivermectin administration on the erythrocyte ghosts, whereas Na+/K+ ATPase activity was calculated. Data analysis was done by one-way analysis of variance (ANOVA), Turkey’s multiple comparison test and Student’s t-test. After treatment, the mean Mg2+ ATPase activity showed a significant 3- fold increase (p<0.0001; F-ratio = 11.765) compared to the mean basal activity. There was no significant effect on Na+/K+ ATPase and Ca2+ ATPase activities (p>0.05; F-ratio = 0.6480), (p>0.05; F-ratio = 0.9151), respectively. There was non-significant difference between the mean basal activities of the different ATPases in the different sexes, but Mg2+ ATPase activity of the males was significantly higher (p<0.05) than females after administration of 20-40 ng/mL of Ivermectin, whereas Na+/K+ ATPase activity was higher in males after the addition of 40-50 ng/mL of the drug. The significant activation of Mg2+ ATPase observed might increase its function of energy generation for maintenance of the biconcave shape of erythrocytes. Ivermectin administration affected the activities of Mg2+ and Na+/K+ ATPases. There is no plausible reason for the observed sex difference.