Effect of Metformin on Potassium-adapted and Nonadapted Diabetic Rats

Purpose: To assess the effects of potassium adaptation on some biochemical parameters in diabetic rats treated with metformin.
Methods: Diabetes was induced via intraperitoneal administration of streptozotocin in potassiumadapted and non-adapted rats and, then metformin (350 mg/kg) was administered orally. The following parameters were then evaluated 24 h after drug administration: urine volume, plasma glucose, plasma and urine creatinine and creatinine clearance. Lipid profiles and plasma and urine urea were also determined.
Results: The blood glucose of the potassium-adapted diabetic group was not significantly reduced on treatment with metformin, compared to non-adapted diabetic rats which were significantly reduced (p < 0.05) on metformin treatment. The potassium-adapted group treated with metformin had significantly higher creatinine clearance (p < 0.05) than the non adapted group. Urine volumes for both the diabetic and the potassium-adapted diabetic rats were significantly lower (p < 0.05) on treatment with metformin.
Conclusion: The results indicate that potassium adaptation induces resistance to treatment with metformin and increases creatinine clearance in diabetic rats.