BACKGROUND: Salt-sensitive hypertension in the Dahl rat is associated with abnormalities in both calcium (Ca2+) and sodium (Na) homeostasis. OBJECTIVE: To test the hypothesis that salt-induced abnormal Ca(2+) handling in Dahl salt-sensitive (DSS) rats is associated with negative Ca(2+) balance and bone disease. METHODS: Ca(2+) excretion in acute and chronic Na(+) loading and electrolyte and water balance were determined by balance studies in Dahl salt-resistant (DSR) and salt-sensitive (DSS) rats fed 8 or 0.1% NaCl for 4 weeks. A dry ashing procedure was used to determine Na(+), Ca(2+), and water content and their association with blood pressure in the rats. RESULTS: When fed 8% NaCl, DSS rats initially maintained a positive Ca(2+) balance and showed decreased natriuresis compared with DSR rats. During the course of Na(+) loading, DSS rats increased natriuresis and calciuresis. After 4 weeks of salt loading, cumulative Na balance was greater and cumulative Ca(2+) balance was less in DSS than in DSR rats. In addition, DSS rats developed osteopenia. Bone mineral content correlated inversely with blood pressure in DSS rats. Acute saline volume expansion in DSS rats demonstrated their ability to excrete the Na load fully, but led to an exaggerated renal loss of Ca(2+) compared with DSR rats. CONCLUSION: DSS, but not DSR, develop Ca(2+) loss and ostopenia during chronic Na(+) loading. We speculate that Na retention in DSS rats fed a high Na diet may be in part a compensatory mechanism to maintain Ca(2+) balance.
BACKGROUND:Salt-sensitive hypertension in the Dahlrat is associated with abnormalities in both calcium (Ca2+) and sodium (Na) homeostasis. OBJECTIVE: To test the hypothesis that salt-induced abnormal Ca(2+) handling in Dahlsalt-sensitive (DSS) rats is associated with negative Ca(2+) balance and bone disease. METHODS:Ca(2+) excretion in acute and chronic Na(+) loading and electrolyte and water balance were determined by balance studies in Dahlsalt-resistant (DSR) and salt-sensitive (DSS) rats fed 8 or 0.1% NaCl for 4 weeks. A dry ashing procedure was used to determine Na(+), Ca(2+), and water content and their association with blood pressure in the rats. RESULTS: When fed 8% NaCl, DSSrats initially maintained a positive Ca(2+) balance and showed decreased natriuresis compared with DSRrats. During the course of Na(+) loading, DSSrats increased natriuresis and calciuresis. After 4 weeks of salt loading, cumulative Na balance was greater and cumulative Ca(2+) balance was less in DSS than in DSRrats. In addition, DSSrats developed osteopenia. Bone mineral content correlated inversely with blood pressure in DSSrats. Acute saline volume expansion in DSSrats demonstrated their ability to excrete the Na load fully, but led to an exaggerated renal loss of Ca(2+) compared with DSRrats. CONCLUSION:DSS, but not DSR, develop Ca(2+) loss and ostopenia during chronic Na(+) loading. We speculate that Na retention in DSSrats fed a high Na diet may be in part a compensatory mechanism to maintain Ca(2+) balance.
Authors: Agnes Schröder; Patrick Neubert; Jens Titze; Aline Bozec; Wolfgang Neuhofer; Peter Proff; Christian Kirschneck; Jonathan Jantsch Journal: JCI Insight Date: 2019-12-05
Authors: Shaleka L Eley; Crystal M Allen; Cicely L Williams; Richard D Bukoski; Mildred A Pointer Journal: Am J Hypertens Date: 2008-05-01 Impact factor: 2.689
Authors: Jan Šilhavý; Petr Mlejnek; Miroslava Šimáková; František Liška; Jan Kubovčiak; Eva Sticová; Michal Pravenec Journal: Biomedicines Date: 2022-02-04