Myocardial calcification and hypertension following chronic renal failure and ameliorative effects of furosemide and captopril

Objectives: The aim of this study was to prevent metastatic myocardial calcification and hypertension following chronic renal failure (CRF). Methods: A total of 50 male Sprague-Dawley rats were allocated to one of five groups: the control group (sham), the NxNT group (nephrectomized rats receiving no treatment), the NxFuro group (nephrectomized rats treated with furosemide), the NxCap group (nephrectomized rats treated with captopril) and the NxFuroCap group (nephrectomized rats treated with furosemide and captopril). Surgery (5/6 nephrectomy) was performed to induce CRF. Oral treatment with furosemide (20 mg/kg) and/or captopril (0.05 mg/kg) was given twice daily for 5 weeks. Parameters were studied after 5 weeks. Results: In the NxNT group, arterial blood pressure was significantly increased compared with the controls. Monotherapy with furosemide or captopril and both in combination maintained blood pressure to near or below control. Myocardial and remnant-kidney calcification was detected in NxNT rats, but calcification was absent in the NxFuroCap rats. Cardiac hypertrophy and fibrosis was observed in the NxNT group but not in treatment groups. Both plasma inorganic phosphate and Ca²⁺ significantly increased in the NxNT group, but the difference was not significant in the treatment groups. Conclusion: Furosemide, either alone or in combination with captopril, is capable to prevent myocardial calcification, cardiac hypertrophy and hypertension, maintaining blood Ca²⁺ and phosphate levels by slowing CRF.