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Long‐term High Salt Diet Causes Hypertension and Impairs Renal VEGF Signaling System in Sprague‐Dawley Rats
Author(s) -
Bailey Amelia Purser,
Tan Wei,
Shparago Megan,
Gu JianWei
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a307-d
Subject(s) - endocrinology , medicine , vascular endothelial growth factor , blood pressure , pathogenesis , urinary system , kidney , mean arterial pressure , vegf receptors , heart rate
Clinical studies suggest that the inhibition of vascular endothelial growth factor (VEGF) is associated with hypertension. However, the role of VEGF in the pathogenesis of hypertension remains in question. We used Sprague‐Dawley (SD) rats to test the hypothesis that chronic dietary salt‐induced hypertension and renal injury are associated with an impaired renal VEGF signaling system. Four 10‐wk‐old male SD rats received a high sodium diet (HS, 8%) for 8 weeks, and another group of four SD rats received a normal sodium diet (NS, 0.5%) for 8 weeks. Weekly monitoring through a tail cuff showed that blood pressure increased significantly after 6, 7, & 8 wks in HS group, compared to NS group. In the end, mean arterial pressure (MAP) was determined in conscious rats by continuous monitoring through a catheter placed in the carotid artery; MAP was significantly higher in HS than NS group (140±2.3 vs. 112±6.1 mmHg, P=0.0104). ELISA demonstrated that there were no significant changes in plasma levels of VEGF and sFlt‐1 (an endogenous VEGF inhibitor) between HS and NS groups. Interestingly, total urinary excretion of sFlt‐1 was significantly higher in HS than NS group (9.3 vs. 2.1 ng/24 h urine; P<0.01). Renal VEGF protein levels significantly decreased in HS group, compared to NS group (68.1±3.4 vs. 84.3±4.2 pg/mg total protein; P<0.01). These findings suggest that a long‐term high salt diet causes hypertension and impairs the renal VEGF signaling system in Sprague‐Dawley rats. This study also demonstrates a novel animal model for studying mechanisms of hypertension, especially dietary salt‐induced hypertension, in relation to VEGF inhibition. (NIH/HL51971 & NIH/AA013821)