ABSTRACT
BACKGROUND: Ferulic acid (FA) is a naturally occurring nutritional compound. Although it has been shown to have antihypertensive effects, its effects on vascular function have not been intensively established. The aim of this study was to assess the vasoreactivity of FA in chronic two-kidney, one-clip (2K1C) renal hypertensive rats. METHODS: Hypertension was induced in 2K1C rats by clipping the left renal artery and age-matched rats that received a sham treatment served as a control. Thoracic aortas were mounted in tissue baths to measure isometric tension. The effects of FA on vasodilatory responses were evaluated based on contractile responses induced by phenylephrine in the aortic rings obtained from both 2K1C and sham rats. Basal nitric oxide (NO) bioavailability in the aorta was determined by the contractile response induced by NO synthase inhibitor N (G)-nitro-l-arginine methyl ester (l-NAME). RESULTS: FA induced concentration-dependent relaxation responses which were greater in 2K1C hypertensive rats than in sham-clipped control rats. This relaxation induced by FA was partially blocked by the removal of endothelium or by pretreating with l-NAME. l-NAME-induced contractile responses were augmented by FA in 2K1C rats, while no significant differences were noted in sham rats. FA improved acetylcholine-induced endothelium-dependent vasodilation in 2K1C rats, but not in sham rats. The simultaneous addition of hydroxyhydroquinone significantly inhibited the increase in acetylcholine-induced vasodilation by FA. CONCLUSION: These results suggest that FA restores endothelial function by altering the bioavailability of NO in 2K1C hypertensive rats. The results explain, in part, the mechanism underlying the vascular effects of FA in chronic renal hypertension.
ABSTRACT
Rhabdomyolysis is a rare complication that emerges in a variety of infectious diseases, such as tsutsugamushi infection. In this study, we report a 71-year-old female patient with tsutsugamushi infection who exhibiting rhabdomyolysis and acute renal failure. On admission, an eschar, which is characteristic of tsutsugamushi infection, was found on her right flank area. Moreover, her tsutsugamushi antibody titer was 1:40960. The elevated values of serum creatinine phosphokinase (CPK), aldolase, creatinine and dark brown urine secondary to myoglobinuria are consistent with indications of rhabdomyolysis and acute renal failure due to tsutsugamushi infection. Her health improved without any residual effects after treatment with doxycyclin and hydration with normal saline.