2,3,5,4'-tetra-hydroxystilbene-2-O-glucoside (THSG), the water-soluble active components extracted from dried tuber root of Polygonum multiflorum (Polygonaceae), can promote the release of nitric oxide (NO) from vascular endothelial cells and has strong antioxidation. The postconditioning's protection of THSG on cardiac ischemia-reperfusion injury and the mechanism were investigated. After reperfusion for 3 h following occlusion of rat left anterior descending coronary artery (LAD) for 30 min, SalphaT recovery speed, arrhythmia and cardiac infarct size were observed. The ischemic size and infarct size was identified by using Evans blue and TTC staining methods respectively. The results showed that the infarct size in THSG 7. 5 mg/kg postconditioning group was significantly decreased from 43.6% +/- 9.1% in mode group to 16.5% +/- 6.5% (P < 0.01). SalphaT recovery was quicker and the incidence of arrhythmia (55.6% vs 100%, P < 0.05) was significantly lower than in control group. The infarct size in THSG+glybenclamide group was greater than in THSG group, but equivalent to that in control group (46.8% +/- 9.8% vs 43.6% +/- 9.1%, P> 0.05), SalphaT recovery speed slower and the incidence of arrhythmia also lower (33.3% vs 100%, P < 0.01), suggesting that glybenclamide could abolish the effects of THSG postconditioning reducing the cardiac infart size. It was concluded that THSG administration before reperfusion could effectively alleviate the cardiac reperfusion injury and possessed the postconditioning effects of reducing cardiac infarct size, which might be related with the K(ATP) channel opening.
Zn,Fe co-doped near stoichiometric LiNbO3 crystals with variant Zn concentrations and with same Fe concentrations were grown by top-seeded-solution-growth (TSSG) method. The optical damage resistances of SLN crystals were studied by the method of transmittance facula distortion. The UV-Vis spectra showed that the grown undoping crystal had a composition very close to stoichiometric LiNbO3 crystal, and the absorption edges moved as the doping concentration changed. The optical damage experiments showed that, the crystal with 2mol% of Zn was with high resistance to optical damage, and the optical damage resistance was improved evidently as the Zn concentration increased further.
Objectives: To measure and compare the tissue oxygenation of gastrocnemius during ischemic and reperfusion (I&R) to lower limbs through two different ways; establish a method for remote ischemic preconditioning(RIPC) through intermittent Seiza and observe its effect on capillary fragility of forearm skin. Methods: 12 college students participated in the measurement of tissue oxygenation in gastrocnemius (using ANT+,MOXY-3) during I&R either through intermittent Seiza or blood pressure cuff inflated to 200 mmHg around thigh , taken 5 min reperfusion following 5 min ischemia as a cycle, repeat 3 such cycles in one RIPC. Check the capillary fragility in the forearm of 33 students whom were in either experimental or control group at pre-, 2 weeks and 4 weeks after the daily intermittent Seiza RIPC or not. Results: Tissue oxygenation in gastrocnemius at 1,3,5 minute of ischemic decreased significantly during both ways compared with before ischemic, but intermittent Seiza can make it decrease more rapidly and thoroughly than that of blood pressure cuff inflation. The forearm skin capillary fragility reduced significantly compared with that of the control group after 4 weeks daily intermittent Seiza RIPC. Conclusions: Intermittent Seiza is an effective and easy way for RIPC, and can improve the quality of skin capillary after 4 weeks daily practice.
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