Effects of a chronic high-salt diet on large artery structure: role of endogenous bradykinin

Abstract

Bradykinin activity could explain the blood pressure increase during NaCl loading in hypertensive animals, but its contribution on vascular structure was not evaluated. We determined cardiac mass and large artery structure after a chronic, 4-mo, high-salt diet in combination with bradykinin B2-receptor blockade by Hoe-140. Four-week-old rats were divided into eight groups according to strain [spontaneously hypertensive rats (SHR) vs. Wistar-Kyoto (WKY) rats], diet (0.4 vs. 7% NaCl), and treatment (Hoe-140 vs. placebo). In WKY rats, a high-salt diet significantly increased intra-arterial blood pressure with minor changes in arterial structure independently of Hoe-140. In SHR, blood pressure remained stable but 1) the high-salt diet was significantly associated with cardiovascular hypertrophy and increased arterial elastin and collagen, and 2) Hoe-140 alone induced carotid hypertrophy. A high-salt diet plus Hoe-140 acted synergistically on carotid hypertrophy and elastin content in SHR, suggesting that the role of endogenous bradykinin on arterial structure was amplified in the presence of a high-salt diet.