Abstract 17303: Protective Roles of Corin Against High Salt-induced Renal Damage
Introduction and Hypothesis: Dietary sodium and potassium affect the fluctuation of blood pressure and renal function. With its activity to convert pro-atrial natriuretic peptide (pro-ANP) to biologically active ANP, corin regulates blood pressure, cardiac and renal functions. We hypothesize that corin plays an essential role in ameliorating the high salt-induced renal damage through its regulation of salt and water homeostasis.
Methods and Results: Forty-two volunteers (28-65 years of age) were intervened with three sequential diets: a low salt diet (3.0 g/day NaCl) for 7 days, a high salt (HS) diet (18.0 g/day NaCl) for 7 days, followed by a high salt diet with potassium supplementation (18.0 g/day NaCl and 4.5 g/day KCl) for 7 days. The systolic blood pressure and urinary microalbumin level (U-MALB) of the 42 subjects were augmented in the period of HS diet compared to those at the baseline level (117.3±2.7 mmHg vs. 108.7±1.8 mmHg, p<0.05; 8.21±0.89 mg/day vs. 4.89±0.34 mg/day, p<0.05). Such changes were reversed by potassium supplementation (107.5±1.9 mmHg; 5.87±0.6 mg/day; p<0.05). ELISA assay performed on the collected sera showed that HS diet increased the level of corin (0.553±0.05 ng/ml) compared to low-salt period (0.416±0.021 ng/ml, p<0.05). With potassium supplementation, the serum corin level decreased (0.356±0.02 ng/ml, p<0.05). Furthermore, serum corin level was positively correlated with that of U-MALB (p<0.05). These data suggest that corin may have a protective role in the kidney damage by HS diet. In order to validate the corin level changes responding to HS and potassium supplementation, we fed Sprague Dawley rats 8% HS or 8% HS with potassium for 1, 3, 7 days. The levels of renal corin, ANP and proprotein convertase subtilisin/kexin type 6 (PCSK6) which is the corin activator were enhanced by the HS diet, which declined after potassium supplementation. However, the ANP inhibited-molecules relative to sodium-water retention such as aquaporin 2 (AQP2) and β-epithelial sodium channel (β-ENaC) had a reciprocal response in the kidney.
Conclusions: Our findings suggest that corin positively correlates with high salt-induced U-MALB level, which may protect renal damage through increased sodium and water excretion.
Author Disclosures: J. Zhang: None. Y. Yin: None. Y. Wang: None. Y. Lu: None. C. Chu: None. Y. Miao: None. M. Martin: None. Z. Yuan: None. J.Y. Shyy: None. J. Mu: None.
- © 2016 by American Heart Association, Inc.