当前位置： SCI文献检索 > LIFE SCIENCES期刊下所有文献 > Effects of high sodium intake diet on the vascular reactivity to phenylephrine on rat isolated caudal and renal vascular beds: Endothelial modulation.

Effects of high sodium intake diet on the vascular reactivity to phenylephrine on rat isolated caudal and renal vascular beds: Endothelial modulation.

Abstract：

:High salt intake is involved in the genesis of hypertension and vascular changes in salt-sensitive patients. Although many mechanisms have been proposed, the underlying mechanisms of these alterations in healthy rats are not completely elucidated. The aim of this study was to investigate if male Wistar rats fed a high salt diet, NaCl 1.8% in drinking water for 4 weeks, develop changes in the pressor reactivity of isolated tail and renal vascular beds. Salt treatment increased mean arterial pressure (SALT = 124 +/- 2.2 vs. CT = 111 +/- 3.9 mmHg; p < 0.01) and urinary sodium excretion in the absence of changes in sodium plasma levels. Pressor reactivity was generated in isolated tail and kidney vascular beds as dose-response curves to phenylephrine (PHE = 0.01 to 300 microg). SALT increased the reactivity (E(max): SALT = 378 +/- 15.8 vs. CT = 282 +/- 10 mmHg; p < 0.01) without changing the sensitivity (pD(2)) to PHE in the tail vascular bed. However, these parameters did not change in the renal bed. In subsequent studies on the isolated caudal vascular bed, we found that endothelial damage, but not L-NAME (100 microM) or indomethacin (10 microM), abolished the increment in E(max) to PHE induced by SALT. On the other hand, losartan (100 microM) reduced E(max) in SALT to CT values. Additionally, local angiotensin-converting enzyme activity in segments from tail artery increased by 95%. In conclusion, 4 weeks of high salt diet increases blood pressure and induces specific territorial vascular changes in response to PHE. Results also suggest that the increment in E(max) in the tail vascular bed from SALT rats was endothelium-dependent and was mediated by the activation of the local renin-angiotensin system.

journal_name

Life Sci

journal_title

Life sciences

authors

dos Santos L,Gonçalves MV,Vassallo DV,Oliveira EM,Rossoni LV

doi

10.1016/j.lfs.2005.09.028

subject

Has Abstract

pub_date

2006-04-04 00:00:00

pages

2272-9

issue

eissn

0024-3205

issn

1879-0631

pii

S0024-3205(05)01061-1

journal_volume

pub_type

杂志文章

在线工具

Effects of high sodium intake diet on the vascular reactivity to phenylephrine on rat isolated caudal and renal vascular beds: Endothelial modulation.