Effect of iron on pancreatic beta cell function and insulin resistance in female albino rats
Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: Forty-eight Wistar rats (150-200g) were divided into 6 groups as follows; Group 1 (control) received 0.3ml distilled water, groups 2, 3, 4, 5 and 6 received iron (10mg/kg, 20mg/kg, 40mg/kg, 80mg/kg and 160mg/kg respectively) daily for 12days. Blood from the tail vein of each animal was assessed for blood glucose level on days 0, 3, 6 and 12 using glucometer. At 12 days post iron treatment, blood (3ml) was obtained from the retro-orbital sinus of each animal and allowed to coagulate. Serum obtained was analysed for insulin concentration using ELISA method. Histopathology of the pancreas was assessed using Hematoxylin and Eosin technique. Data were expressed as Mean ± SEM and analyzed using two-way ANOVA at P<0.05. Results: Blood glucose level, insulin concentration, insulin resistance and pancreatic beta cell function increased significantly with increased concentration of iron. Histology of the pancreas showed fat infiltration of both acini and islets with increased iron concentration. Mild inflammation of the islets was observed at 160mg/kg. Conclusion: Administration of iron at 40mg/kg and above in female rats caused hyperglycaemia, insulin resistance, hyperinsulinaemia, inflammation and pancreatic beta cell dysfunction thus predisposing the animal to type 2 diabetes mellitus.
Keywords: Iron, Hyperglycaemia, Insulin resistance, Hyperinsulinaemia, inflammation, Beta cell dysfunction.