Effects of salt loading on sympathetic activity and blood pressure in anesthetized two-kidney, one clip hypertensive rats


BOSNIAN JOURNAL OF BASIC MEDICAL SCIENCES, vol.11, no.4, pp.228-233, 2011 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 11 Issue: 4
  • Publication Date: 2011
  • Doi Number: 10.17305/bjbms.2011.2555
  • Page Numbers: pp.228-233


In this study, we investigated the effects of salt loading on sympathetic pressor activity, cardiac autonomic activity, mean arterial pressure (MAP), heart rate (HR) and on the relations between them in anesthetized two-kidney, one clip (2K1C) hypertensive rats. We submitted rats to either renal artery clipping or sham operation. Distilled water or 0.5 % NaCl was given orally to the clipped and sham-operated control rats for 4 weeks. Then, MAP and HR differences between pre- and post- autonomic blockade were evaluated as indexes of sympathetic pressor and cardiac autonomic activity, respectively. The autonomic blockade decreased MAP to the similar levels in all groups (between 81.7 +/- 7.6-87.3 +/- 7.1 mmHg). Sympathetic pressor activity was greater in the clipped rats than in its sham-operated controls only under salt loading (55.3 +/- 6.2 vs. 37.0 +/- 4.1 mmHg, p<0.05). Cardiac autonomic activity was, predominantly, sympathetic and more in the clipped group than in the sham-operated rats under distilled water (48.3 +/- 8.6 vs. 19.7 +/- 7.0 beats/min, p<0.05) but not under salt loading. Salt loading inverted the relationship between HR and cardiac autonomic activity in 2K1C hypertensive rats (r=0.76,p=0.046 vs. r=0.89,p=0.019). These results suggest that salt loading may have augmented the effect of renovascular constriction on MAP by affecting the sympathetic pressor activity and the elation between cardiac autonomic activity and HR in 2K1C hypertensive rats. (C) 2011 Association of Basic Medical Sciences of FBIH. All rights reserved