Effect of Vitamin E Supplementation on Intestinal Barrier Function in Rats Exposed to High Altitude Hypoxia Environment

The study was conducted to investigate the role of vitamin E in the high altitude hypoxia-induced damage to the intestinal barrier in rats. Sprague-Dawley rats were divided into control (Control), high altitude hypoxia (HH), and high altitude hypoxia+vitamin E (250 mg/kg BW*d) (HV) groups. After the third day, the HH and HV groups were placed in a hypobaric chamber at a stimulated elevation of 7000 m for 5 days. The rats in the HV group were given vitamin E by gavage daily for 8 days. The other rats were given equal volume saline. The results showed that high altitude hypoxia caused the enlargement of heart, liver, lung and kidney, and intestinal villi damage. Supplementation with vitamin E significantly alleviated hypoxia-caused damage to the main organs including intestine, increased the serum superoxide dismutase (SOD) (p< 0.05), diamino oxidase (DAO) (p< 0.01) levels, and decreased the serum levels of interleukin-2 (IL-2) (p< 0.01), interleukin-4 (IL-4) (p<0.001), interferon-gamma (IFN-gamma) (p<0.01) and malondialdehyde (MDA) (p<0.001), and decreased the serum erythropoietin (EPO) activity (p<0.05). Administration of vitamin E significantly increased the S-IgA (p<0.001) in ileum and significantly improved the expression levels of occludin and IkappaBalpha, and decreased the expression levels of hypoxia-inducible factor 1 alpha and 2 alpha (HIF-1alpha and HIF-2alpha), Toll-like receptors (TLR4), P-IkappaBalpha and nuclear factor-kappaB p65(NF-kappaB P65) in ileum compared to the HH group. This study suggested that vitamin E protectis from intestinal injury caused by high altitude hypoxia environment. These effects may be related to the HIF and TLR4/NF-kappaB signaling pathway.

Studies on Changes of Brain Energy Metabolism in Diabetic Rats by 31 P Magnetic Resonance Spectroscopy / 分析化学

Considerable attention has been directed toward studying the impact of diabetes on the central nervous system. The current study investigates the biochemical changes in the brain tissue of streptozotocin (STZ)-induced diabetic rat using 31P magnetic resonance spectroscopy (31P MRS). The 31P NMR spectra of the whole brain show no significant changes of phosphomonoesters and phosphodiesters levels one week after STZ induction, suggesting no apparent structural changes in cell membranes. The results identifies the increased level of adenosine diphosphate, negligible changes of phosphocreatine ( PCr ) and adenosine triphosphate ( ATP) , but the decreased ratio of PCr/ATP, indicating that PCr plays a role of balancing the energy. Moreover, the decreased pH value indicates the changes of the intracellular environment in STZ-diabetic brains in rats. After 15 weeks of STZ injection, the metabolism of phospholipid membrane and brain energy metabolism has been obviously disturbed. Our study successfully shows that 31 P MRS can not only study phospholipid and energy metabolism non-invasively, but also measure intracellular pH and other important biochemical information. All of these spectroscopic characterizations contribute significantly to the understanding of pathogenesis and evolution of diabetes, and provide theoretical basis for early diagnosis and clinical treatment in diabetes.