BackgroundIn the previous study, active extract of Radix Scrophularia (ACRS) demonstrated beneficial effects on ventricular remodeling induced by coronary artery ligation and lowered blood pressure in rats. And ACRS also exhibited the effect on lowering the blood pressure in spontaneously hypertensive rats (SHRs). The aim of this study is to explore the effects of ACRS on ventricular remodeling in SHRs and underlying mechanisms.ResultsACRS significantly lowered the blood pressure, decreased the heart mass indexes, inhibited the deposition of perivascular and interstitial, attenuated the accumulation of types I and III collagen, reduced the tissue angiotensin II, serum norepinephrine and tumor necrosis factor-α concentrations. The underlying mechanisms may be related to downregulating the mRNA expressions of collagen type I, transforming growth factor-β1 and angiotensin converting enzyme, suppressing the phosphorylation of extracellular signal regulated kinase 1/2, c-Jun N-terminal kinase (JNK/SAPK) and p38 mitogen-activated protein kinases (p38 MAPK).ConclusionContinuous treatment of SHRs with ACRS for 21 weeks reduced blood pressure, myocardial hypertrophy and the amount of interstitial and perivascular collagen, which indicated that ACRS could prevent hypertensive ventricular remodeling. This can be attributed to suppression of the sympathetic nervous and renin angiotensin aldosterone system through the inhibition of ERK 1/2, JNK and p38 MAPK pathways.
Sr3Ti2O7ceramics with pure Ruddlesden-Popper phase (RP) were synthesized by conventional solid state method. The influences of the Bi2O3addition, the calcination temperature, and the sintering temperature on the phase transition were studied. The results showed that for the samples without doping Bi2O3, the main phase of calcined powders is Sr3Ti2O7, but pure Sr3Ti2O7phase cannot be obtained in the sintered ceramics because of the Sr3Ti2O7decomposition. For the samples doping with Bi2O3, although the main phase of the calcined powder is SrTiO3, the single RP phase Sr3Ti2O7can be obtained after sintering, which should be attributed to the formation of Sr3Bi2O6phase during calcination stage. Bi2O3addition is beneficial to the formation of the Sr3Ti2O7RP phase.
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