Dietary Salt-Induced Kidney Damage

At 6 weeks of age, DSS rats were selected at random to receive rat chow containing normal salt (NS: 0.5% NaCl, Oriental Yeast, Tokyo, Japan) or high salt (HS: 4% NaCl, Oriental Yeast) for 14 weeks from 6 to 20 weeks of age. From 6 to 20 weeks of age, HS-fed DSS rats were further treated with either vehicle (0.5% methyl cellulose, Nacalai Tesque, Kyoto, Japan), olmesartan (OLM: oral gavage; 10 mg/kg body weight/day, p.o.; Daiichi-Sankyo Co., Ltd., Tokyo, Japan), azelnidipine (AZEL: 3 mg/kg body weight/day, p.o.; Daiichi-Sankyo Co., Ltd.), their combination, or hydralazine (HYD: 50 mg/kg body weight/day, p.o.; Wako Co., Ltd., Osaka, Japan). The doses of OLM and AZEL were chosen on the basis of results from previous rat studies [12] (link), [20] (link). Preliminary studies also showed that HYD at 50 mg/kg substantially decreased blood pressure in HS-treated DSS rats (data not shown). Kidneys were perfused with saline and harvested under sodium pentobarbital anesthesia (65 mg/kg) at 10, 15 and 20 weeks of age (n = 7 for each). All data from Protocol-1 are shown as in Supplemental Figures.