Effects of Potassium and Magnesium on Some Hemodynamic and Renal Function Related Parameters in 2k1c Hypertensive Rats

Abstract

–The present study was done to investigate the effect of potassium and magnesium on aldosterone level, systolic blood pressure (SBP), heart rate (HR); renal function test parameters, serum nitric oxide (NO) and malondialdehyde (MDA) in 2-kidney, 1-clip (2K1C) hypertensive rats. The experimental rats were divided into six groups, each with seven rats and the treatments were continued for 4 weeks: Group 1: Control, Group 2: Sham operated surgery rats ,Group 3: 2K1C hypertensive rats , Group4: 2K1C + Potassium chloride ,KCl (80 gms/Kg diet) , Group5: 2K1C + Magnesium sulphate ,MgSO4 (80 gms/Kg diet), Group6: 2K1C +KCl+MgSO4 (160 gms/Kg diet). The results showed that renal artery constriction caused significant elevation in SBP and HR. Furthermore, serum levels of aldosterone, serum MDA, sodium ions (Na + ), chloride ions ( Cl ), creatinine and urine Na + levels were also elevated significantly in 2K1C hypertensive rats. On the other hand, administration of potassium decreased significantly SBP,HR, serum level of aldosterone, MDA, serum Na + and creatinine, while, serum levels of NO, K + and glomerular filtration rate (GFR) significantly increased compared with values in 2K1C hypertensive rats. Magnesium supplementation in 2K1C hypertensive rats caused significant decrease in SBP, HR, serum aldosterone level, serum MDA, Cl , calcium ions (Ca 2+ ) and increased serum levels of NO and magnesium ions (Mg 2+ ) levels compared with 2K1C hypertensive group. Moreover, administration of potassium in combination with magnesium in 2K1C hypertensive rats caused significant decrease in SBP, serum aldosterone level, HR, serum MDA, Na + , Cl , Ca 2+ , creatinine and serum levels of NO, K + , Mg 2+ and GFR were increased significantly, while, no significant change recorded in urine Na + levels compared all values with 2K1C hypertensive rats. Conclusion: The blood pressure lowering characteristic of potassium and magnesium was attributed to increase serum NO levels. The reduced serum MDA levels in hypertensive rats suggest that potassium and magnesium have antioxidant properties by reducing oxidative stress and preventing lipid peroxidation. Keywords––Potassium, Magnesium, Two-Kidney One-Clip hypertensive rats, Renin-angiotensin system,