High NaCl diets increase alpha 2-adrenoceptors in renal cortex and medulla of NaCl-sensitive spontaneously hypertensive rats.

Academic Article

Abstract

  • Diets high in NaCl simultaneously elevate renal alpha 2-adrenoceptor binding and exacerbate hypertension in young NaCl-sensitive spontaneously hypertensive rats (SHR-S). The present study tests the hypothesis that in SHR-S on a high NaCl diet, an upregulation of renal alpha 2-adrenoceptors is present in densely innervated areas of the kidney, and this precedes the increase in blood pressure. Seven week old SHR-S fed on a high (8%) compared to basal (1%) NaCl diet for 2 weeks displayed significantly exacerbated hypertension and elevated renal alpha 2-adrenoceptor binding in both cortex and medulla. In contrast one week on the high NaCl diet did not alter renal alpha 2-adrenoceptor number or blood pressure in SHR-S. Autoradiographic experiments demonstrated that the NaCl-induced upregulation of alpha 2-adrenoceptors occurs in all areas of the renal cortex and medulla. None of these differences were observed in NaCl-resistant, Wistar-Kyoto rats (WKY). Further, the high NaCl diet did not alter renal alpha 1-adrenoceptor binding in SHR-S or WKY. Together with previous findings, these data suggest that the NaCl-induced upregulation of renal alpha 2-adrenoceptors is not specific to densely innervated regions of the kidney.
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    Keywords

  • Animals, Autoradiography, Catecholamines, Diet, Hypertension, Kidney Cortex, Kidney Medulla, Kinetics, Male, Rats, Rats, Inbred SHR, Rats, Inbred WKY, Receptors, Adrenergic, alpha, Sodium Chloride, Time Factors
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    Author List

  • Sripairojthikoon W; Wyss JM
  • Start Page

  • 355
  • End Page

  • 365
  • Volume

  • 167
  • Issue

  • 3