Expression of cardiac tissue prorenin, renin, (pro)renin receptor, angiotensinogen and angiotensin II AT1 receptor.

<p>Expressions of cardiac tissue (a) prorenin, (b) renin, (c) (pro)renin receptor, (d) angiotensinogen and (e) angiotensin AT1 receptor in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05.</p

Masson-Trichrome staining and hematoxylin-eosin staining of left ventricle.

<p>Representative (a) short-axis sections of cardiac ventricle stained with Masson-Trichrome (Scale bars: 1 mm), (b) short-axis images of the myocardium and intramuscular arteries with perivascular and interstitial fibrosis stained with Masson-Trichrome (Scale bars: 50 μm), (c) short-axis images of the myocardium and interstitial fibrosis stained with Masson-Trichrome (Scale bars: 50 μm) and (d) short-axis images of the myocardium stained with hematoxylin-eosin (Scale bars: 50 μm) at 12 weeks of age in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). (e) Ratio of myocardial interstitial fibrosis area/ myocardium and (f) Short-axis diameter of cardiomyocytes at 12 weeks of age in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05.</p

Changes in the systolic blood pressure caused by a high salt intake in the WKY and SHR groups.

<p>(a) Systolic blood pressure at 12 weeks of age in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05. (b) Time-course changes in systolic blood pressure in response to a high salt intake in the WKY and SHR groups. Data represent the means ± SEM (n = 7). #: p < 0.05 vs. 6 weeks of age of WKY + HS, †: p < 0.05 vs. 6 weeks of age of SHR + NS, ‡: p < 0.05 vs. 6 weeks of age of SHR + HS.</p

Protocol of the experiment.

<p>Protocol of the experiment.</p

Expression of cardiac tissue p38MAPK, phosphorylated (p)-p38MAPK, HSP27, p-HSP27, ERK1/2, p-ERK1/2, TGF-β1 and GAPDH.

<p>Expressions of cardiac tissue (a) p38MAPK, (b) p-p38MAPK, (c) HSP27, (d) p-HSP27, (e) ERK1/2, (f) p-ERK1/2, (g) TGF-β1 and (h) GAPDH in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05.</p

Echocardiographic findings.

<p>(a) Interventricular septum (IVS) thickness, (b) Left ventricular diastolic dimension (LVDd) and (c) Fractional shortening (FS) at 12 weeks of age in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05. (d) Representative M-mode echo cardiograms at left ventricular levels.</p

Plasma renin activity and plasma angiotensin II concentration.

<p>(a) Plasma renin activity and (b) Plasma angiotensin II concentration in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05.</p

The proposed mechanism by which the combination of hypertension and a high salt intake causes myocardial fibrosis, myocardial perivascular fibrosis and cardiomyocyte hypertrophy, as noted in the present study.

<p>(a) signal transduction through (pro)renin receptors. (b) signal transduction through angiotensin II AT1 receptors. Both a and b contribute to the effects of the combination of hypertension and a high salt intake.</p

Heart weight, lung weight, body weight, heart weight/ body weight ratio and lung weight/ body weight ratio.

<p>(a) Body weight, (b) Heart weight, (c) Heart weight/ body weight ratio, (d) Lung weight and (e) Lung weight/ body weight ratio at 12 weeks of age in the WKY + normal-salt group (WKY+NS), WKY + high-salt group (WKY+HS), SHR + normal-salt group (SHR+NS) and SHR + high-salt group (SHR+HS). Data represent the means ± SEM (n = 7). **: p < 0.01, *: p < 0.05.</p