Effects Of Compound Ion Salt On Functional And Pathological Changes Of Kidney In Spontaneously Hypertensive Rats

Objective: To investigate the effects of compound-ion salt on functional and pathological changes of kidney in spontaneously hypertensive rats.Methods: SHR (male, n=38) were randomized to receive 8% high salt (HS group, n=10); 1% compound-ion salt (CIS group, n=10); 1% compound-ion salt plus 2.25% L-Arg (CIS + L-Arg group, n=9); and 1% normal salt (NS group, n=9) for 12 weeks. ① Throughout the experiments, systolic blood pressure, body weight, urine volume, urinary sodium excretion and urinary protein excretion were measured every three weeks. ② After intervention, all rats were sacrificed, then blood was collected to measure the content of blood glucose, triglyceride and total cholesterol. Plasma sodium and potassium, creatinine clearance rate and fractional excretion of sodium(FENa~+%) were also measured. The content of AngⅡ and NO in plasma and cortex of kidney were measured by radioimmunoassay (RIA). Renal fibrosis and related pathological changes were quantitately evaluated by GIS, TIS and CVF. ③ The protein expression of phosphorylated ERK1/2 in cortex of kidney was analyzed by western blot.Results:1. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could delay the progression of blood pressure in SHR (222 ± 6, 212 ±2 vs. 268 ±4 mmHg, P<0.01).2. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could ameliorate the excretion ofurinary sodium and potassium, and increase FENa+% (0.117 ± 0.015, 0.153 ± 0.016 vs. 0.087 ± 0.027, P<0.05).3. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could decrease urinary protein excretion in these two groups (7.69 ± 1.25, 6.47 ±0.96 vs. 14.56± 1.92 mg/day, PO.01).4. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could promote the production of NO in cortex of kidney (1.92 ±0.58, 2.36 ± 0.7 vs. 1.24 ±0.4 umol/g, PO.01), and inhibite the production of Angll in cortex (1.47+0.08, 1.25 ± 0.08 vs. 1.85 + 0.07 pg/mg, PO.01).5. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could ameliorate the kidney injury(GIS: 1.22 ± 0.15, 1.05 ± 0.11 vs. 1.62 ± 0.14, TIS: 1.33 ± 0.08, 1.22±0.03 vs. 2.19±0.09, PO.01 ), and decrease the deposition of collagen in interstitium (glomerular CVF: 22.79±4.22, 14.60 ±2.29 vs. 38.03 ±2.94, PO.01; tubular CVF: 15.31 ±2.40, 14.12± 1.96 vs. 38.03 ±2.94, PO.01 ) .6. Compared with normal-salt diet, 1% compound-ion salt or 1% compound-ion salt + 2.25% L-Arg intake could decrease the protein expression of p-ERKl in renal tissue (OD: 0.87 ±0.07, 1.17 ±0.23 vs. 1.65 ±0.20, P<0.05), but could not influence the expression of p-ERK2. On the contrary, high salt intake increased the expression of both p-ERKl and P-ERK2 in renal tissue (OD: 1.82 ±0.26 vs. 1.12 ±0.20, 2.13 ±0.46 vs. 1.65±0.20,P<0.05).Conclusion: ? Compound-ion salt intake could maintain the balance...