IMCD cells cultured from Dahl S rats absorb more Na+ than Dahl R rats

Am J Physiol. 1996 Nov;271(5 Pt 2):F1029-36. doi: 10.1152/ajprenal.1996.271.5.F1029.

Abstract

Dahl salt-sensitive (S) rats develop hypertension in response to a high-salt diet, whereas Dahl salt-resistant (R) rats do not. There is good evidence that the Dahl S kidneys have diminished natriuretic capacity. We studied the rate of Na+ transport by primary cultures of the inner medullary collecting duct from these two strains to determine whether there were intrinsic differences. Monolayers obtained from prehypertensive S rats transported Na+ at twice the rate as monolayers from age-matched R rats. Mineralocorticoid and glucocorticoid hormones increased Na+ transport from both strains; the S rat monolayers always displayed higher transport rates than R rat monolayers with the same treatment. The Na+ entry pathway in both S and R rat monolayers was via an Na+ channel. The difference in Na+ transport was not explained by a difference in the metabolism of corticosterone, ATP content, citrate synthase activity, ultrastructural appearance, or rate of maturation. Monolayers from S rats tended to have higher protein and DNA content, but these differences could not account for the difference in Na+ transport. Anion secretion in response to adenosine 3',5'-cyclic monophosphate agonists was similar. These results demonstrate intrinsic differences in renal tubular cells that may play an important role in the pathogenesis of salt-sensitive hypertension.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anions / metabolism
  • Biological Transport
  • Cell Division
  • Cells, Cultured
  • Corticosterone / metabolism
  • Drug Resistance / genetics
  • Electric Conductivity
  • Energy Metabolism
  • Female
  • Hypertension / chemically induced*
  • Hypertension / genetics*
  • Kidney Medulla
  • Kidney Tubules, Collecting / cytology
  • Kidney Tubules, Collecting / drug effects
  • Kidney Tubules, Collecting / metabolism*
  • Rats
  • Rats, Inbred Strains / genetics
  • Sodium / pharmacokinetics*
  • Sodium Chloride / pharmacology*

Substances

  • Anions
  • Sodium Chloride
  • Sodium
  • Corticosterone