CHRONIC TREATMENT WITH NIFEDIPINE PREVENTS DEVELOPMENT OF HYPERTENSION AND ABNORMAL RED-CELL NA plus TRANSPORT IN DAHL-S-RATS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 275  (2) , 248-258
Abstract
Transmembrane Na+ transport was measured in erythrocytes of salt resistant (DR) and salt sensitive (DS) Dahl rats, fed either a standard (0.4%) or high (0.8%) NaCl diet, or a high NaCl diet containing 300 ppm of the Ca entry blocker nifedipine. Whereas salt-loaded DS became severely hypertensive, those treated with nifedipine remained normotensive. With a low NaCl diet, total Na+ efflux and Na+ pump activity was lower in DS than in DR. Cotransport was more active in DS than in DR. After excess Na+ intake, total Na+ efflux was markedly reduced in DS, but normal in nifedipine-treated DS. Cell Na+ content was increased by 52% in salt-loaded DS, but not so in DS chronically treated with nifedipine. Na+ pump was completely suppressed in salt-loaded DS, but normal in DR and rats treated with nifedipine. Na+ pump inhibition apparently might be involved in the development of Dahl rat hypertension, and prevention of salt-induced hypertension by chronic nifedipine treatment also prevents suppression of erythrocytic Na+ pump. This suggests a casual link between its biochemical and therapeutic action.