SGLT2 inhibition has beneficial effects on cardiovascular and renal endpoints but the lowest effective dose is unknown. Effects of the SGLT2 inhibitor, empagliflozin (EMPA) were evaluated in nondiabetic, 5/6 nephrectomy (5/6 Nx) rats. Rats were treated for 8 weeks: Sham + normal diet + placebo (PBO); 5/6Nx + 2% high salt diet (HSD) + PBO; 5/6Nx + HSD + EMPA 1.2 mg/kg/day); 5/6Nx + HSD + telmisartan (5 mg/kg/day); 5/6Nx + HSD + linagliptin (3 mg/kg/day). EMPA increased urinary glucose excretion at dosages eight times lower than currently used low doses. 5/6Nx HSD rats treated with EMPA showed significantly (-29.95/-25.00 mmHg, p<0.001) lower blood pressure (BP) and significantly reduced renal (-33.67%; p<0.05) and cardiac (- 34.85%; p<0.05) fibrosis vs. PBO. Effects of EMPA on BP and renal and cardiac fibrosis were comparable to telmisartan (BP: -31.89/-24.24 mmHg, p<0.001; renal fibrosis -43.96%; p<0.01; cardiac fibrosis: -36.37%; p<0.01) and effects on fibrosis were comparable to linagliptin (renal fibrosis -41.54%; p<0.05; cardiac fibrosis: -50.01%; p<0.001). Many genes were differentially regulated among groups, e.g., transferrin receptor (Trfc), A-kinase anchor protein 1 (Akap1) and mitogen-activated protein kinase 9 (Mapk9) were affected by EMPA and telmisartan while Caspase 1 (Casp1) gene expression was altered by EMPA only in the heart. In the kidney, both EMPA and linagliptin led to differential regulation of pleckstrin homology domain-containing family A member 1 (Plekha1), while only EMPA resulted in differential expression of prostaglandin E synthase (Ptges) and G protein-coupled receptor, class C, group 5, member A (Gprc5a) gene expression. Very low dose EMPA was almost as effective as standard dosages of telmisartan or linagliptin in counteracting BP increase and cardiac and renal fibrosis. The underlying mechanism involves regulation of genes involved in cardiac and renal fibrosis.
S. Zeng: None. A.A. Hasan: Research Support; Self; Boehringer Ingelheim International GmbH. D. Delic: None. Y. Xiong: None. C. Chu: None. L. Yin: None. S. Frankenreiter: Employee; Self; Boehringer Ingelheim Pharma GmbH & Co. KG. Other Relationship; Self; Evotec International GmbH. B. Krämer: Advisory Panel; Self; Boehringer Ingelheim International GmbH. T. Klein: Employee; Self; Boehringer Ingelheim International GmbH. B. Hocher: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.
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