Hydrogen Sulfide Improves Myocardial Remodeling via Downregulated Angiotensin â ¡/AT1R Pathway in Renovascular Hypertensive Rats.

BACKGROUND: Hydrogen sulfide (H2S) is an important endogenous gaseous transmitter in many physiological functions. Plasma H2S decreased, and angiotensin II (Ang II) type 1 receptor (AT1R) increased in the myocardial tissues in 2-kidney 1-clip (2K1C) rats than in normotensive rats. Accumulating evidences suggest that H2S inhibited Ang II/AT1R pathway to regulate cardiovascular function. Therefore, we hypothesized that H2S may exert beneficial effects on myocardial remodeling in 2K1C rat models of renovascular hypertension. METHODS AND RESULTS: Sodium hydrosulfide (NaHS, 56 µmol/kg/day) was administered intraperitoneally to the rats from the 7th day after 2K1C operation. Systolic blood pressure was significantly increased from the first week after the operation and was lowered after NaHS treatment for 4 weeks. H2S could also inhibit the ratio of left ventricle and septum weight to body weight, improve cross-sectional area, and ameliorate ventricular dysfunction. Additionally, the protein expression of AT1R and Ang II serum content were downregulated, whereas superoxide dismutase (SOD) protein was upregulated in 2K1C rats by NaHS treatment for 4 weeks. Furthermore, the reactive oxygen species level and AT1R protein were increased, whereas SOD protein was decreased in cardiomyocytes treated with Ang II compared with the control group. NaHS could reverse these changes. Losartan and N-acetylcysteine could also reverse Ang II-induced changes. CONCLUSIONS: The protective effect of H2S is attributable to the suppression of oxidative stress. This process involves the inhibition of the Ang II/AT1R pathway and upregulation of antioxidant enzymes in 2K1C rats.

[Determination of polysaccharide from Chinese medicine Morinda officinalis how and its trace elements analysis].

Polysaccharide was extracted from morinda officinalis how by back-flowing with 80% ethanol for 1 h, and the method of improved phenol-sulfuric acid spectroscopy was adopted to determine the content of morinda officinalis how polysaccharide. As for its trace elements, the atomic absorption spectroscopy was used to detect the content of Zn, Fe and Cu, which were compared with its fake; and cold atomic fluorometry was applied to determine the trace mercury. The results were satisfactory, which can give reference about the effective components of morinda officinalis how, and will help to exploit it.

Effects of phytoestrogen genistein on myocardial ischemia/reperfusion injury and apoptosis in rabbits.

AIM: To study the effect of genistein (GST) on rabbit heart ischemia/reperfusion (I/R) injury. METHODS: Rabbit heart I/R injury was induced by occluding the left anterior descending coronary artery for 45 min and reperfusing for 180 min. GST (1.0 mg/kg) was intravenously injected 5 min before heart ischemia. Hemodynamic data, infarct size, and cardiomyocytic apoptosis were measured. The pathologic changes of I/R myocardium were observed. RESULTS: During the I/R, heart rate, mean arterial blood pressure, myocardial oxygen consumption, left ventricular (LV) -dp/dtmax and +dp/dtmax were decreased progressively. The infarct size was occupied 60.23 %+/-3.97 % (% of area at risk) in vehicle +I/R group while GST reduced the infarct size to 39.62 %+/-4.30 % (P<0.01). DNA ladder pattern in myocardium was revealed by agarose gel electrophoresis in vehicle +I/R group while was not found in GST+I/R group. Apoptotic cardiomyocytes were sparse within ischemic myocardium at risk in GST+I/R group as compared with that in vehicle +I/R group (TUNEL stain). Apoptosis rate in ischemic myocardium from vehicle +I/R and GST+I/R groups detected by flow cytometry were 15.33 %+/-1.31 % and 3.88 %+/-0.33 %, respectively. Fas and Bax protein expressions in ischemic myocardium of vehicle +I/R group were higher than that in GST+I/R group (P<0.01). Bcl-2/Bax ratio in vehicle +I/R group was lower than that in nonischemic myocardium (P<0.01), while in GST+I/R group, the Bcl-2/Bax ratio was higher than that in vehicle +I/R group (P<0.01). CONCLUSION: GST reduced infarct size and apoptosis of myocytes in I/R rabbit heart.