INFLUENCE OF AGE ON SALINE HYPERTENSION IN SUBTOTAL NEPHRECTOMIZED RATS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 33  (2) , 123-128
Abstract
In uninephrectomized immature and adult male rats, 34% renal tissue was removed from the remaining kidney and after 60-days exposure to saline treatment (0.17 mol/1 NaCl solution as only drinking fluid) the mean arterial blood pressure, plasma urea concentration, plasma and extracellular fluid volumes were estimated. In comparison with water-drinking uninephrectomized age-matched controls, the following results were obtained: in both age groups, the loss of tissue from the remaining kidney was fully replaced by compensatory growth of the renal stump; plasma urea concentration remained unchanged in animals operated on when adult, but increased in animals operated on when immature; the interstitial fluid volume increased in both age groups; the plasma volume as well as blood pressure remained unchanged in animals treated when adult, but increased in animals treated when immature. Under conditions of elevated salt intake the loss of renal mass in immature rats was compensated by growth of tissue with a lower excretory ability than in adult ones, this being responsible for the development of hypertension in the younger group.