Diurnal pattern in skin Na+and water content is associated with salt-sensitive hypertension in ETBreceptor-deficient rats

Academic Article

Abstract

  • Impairment in the ability of the skin to properly store Na nonosmotically (without water) has recently been hypothesized as contributing to salt-sensitive hypertension. Our laboratory has shown that endothelial production of endothelin-1 (ET-1) is crucial to skin Na handling. Furthermore, it is well established that loss of endothelin type B receptor (ET ) receptor function impairs Na excretion by the kidney. Thus we hypothesized that rats lacking functional ET receptors (ET -def) will have a reduced capacity of the skin to store Na during chronic high-salt (HS) intake. We observed that ET -def rats exhibited salt-sensitive hypertension with an approximate doubling in the diurnal amplitude of mean arterial pressure compared with genetic control rats on a HS diet. Two weeks of HS diet significantly increased skin Na content relative to water; however, there was no significant difference between control and ET -def rats. Interestingly, HS intake led to a 19% increase in skin Na and 16% increase in water content (relative to dry wt.) during the active phase (zeitgeber time 16) versus inactive phase (zeitgeber time 4, P <\ 0.05) in ET -def rats. There was no significant circadian variation in total skin Na or water content of control rats fed normal or HS. These data indicate that ET receptors have little influence on the ability to store Na nonosmotically in the skin during long-term HS intake but, rather, appear to regulate diurnal rhythms in skin Na content and circadian blood pressure rhythms associated with a HS diet. + + + + + + + + + B B B B B B B
  • Digital Object Identifier (doi)

    Author List

  • Speed JS; Hyndman KA; Kasztan M; Johnston JG; Roth KJ; Titze JM; Pollock DM
  • Start Page

  • R544
  • End Page

  • R551
  • Volume

  • 314
  • Issue

  • 4