ABSTRACT
BACKGROUND:In high-intensity exhaustive exercise process, the body must bear the exercise intensity decreasing splanchnic blood flow“ischemia”, at the same time, along with the movement of energy and material consumption, metabolite accumulation and oxidative stress in the body cause pathological damage, leading to a decline in exercise capacity. Thus, what is the impact on kidney filtration barrier? How to adapt to the change of renal tissue? Houttuynia cordata has the functions of heat clearing and detoxifying, dieresis for treating strangurtia, hemostatic, expel ing phlegm to arrest coughing and analgesia, if it has a protective effect on the renal injury caused by acute exhaustive exercise and its mechanism has not been reported in the literature. OBJECTIVE:To explore the effect of acute exhaustive exercise on kidney filtration barrier in rats and the intervention effect of Houttuynia cordata.METHODS:After resting and watching for 3 days, Sprague-Dawley rats received adaptive running for 15 minutes at a speed of 10 m/min on a 0° treadmil . A total of 24 rats, which can finish the running, were selected. They were divided into normal control group, exhaustive exercise group and dosed exhaustive exercise group according to the weight of layer (n=8). Rats in the exhaustive exercise group and dosed exhaustive exercise group on the 10° treadmil received once exhaustive exercise. Dosed exhaustive exercise group received intraperitoneal injection of sodium houttuyfonate 10 mL/kg at 30 minutes before exercises. The normal control group did not do any exercise. RESULTS AND CONCLUSION:Compared with the normal control group, serum urea nitrogen, serum creatinine, urine protein content, malondialdehyde concentration, renal cellapoptosis and apoptosis index were significantly increased, but nitric oxide content and nitric oxide synthase activity in the renal tissue were significantly deceased in the exhaustive exercise group (P<0.05 or 0.01). Glomerular filtration epithelial cells, the kidney filtration barrier of basement membrane and podocyte damage were obvious, showing abundant cellapoptosis, occasional y necrosis. Compared with the exhaustive exercise group, urine protein content, serum creatinine, malondialdehyde concentration, renal cellapoptosis and apoptosis index were significantly reduced, but nitric oxide content and nitric oxide synthase activity were significantly increased in the dosed exhaustive exercise group (P<0.05). No obvious pathological changes were detected, but apoptosis was visible. These findings confirmed that houttuynine made a reduction in renal cellinjury induced by exhaustive exercise and possibly significantly reduced apoptosis, increased nitric oxide synthase content, decreased malonaldehyde, and apparently increased superoxide dismutase activity, and final y protected injured renal tissue induced by exhaustive exercise.
ABSTRACT
Objective We investigated if the proliferative capacity of endothelial progenitor cells was affected by hypoxia and exercise. Methods Twenty four male Sprague-Dawley rats were randomly and averagely divided into 4 groups: (1) living at low altitude (LL), (2) living and training at low altitude (LLTL), (3) living at high altitude (LH), and (4) living at high altitude and training at low altitude (LHTL). Eight-week incremental treadmill exercise and hypoxic simulation were used to establish LHTL animal model. Mononuclear cells from peripheral blood were obtained by density gradient centrifugation 12 hours by the end of 8-week experiment. The cells were suspended in conditioned medium 199 for culturing in vitro. Their phenotypes were confirmed by uptake of acetylated LDL and binding of fluoresce in isothiocyanate (FITC)-labeled Ulex europaeus agglutinin 1 (UEA-1) lectin. Inverted microscopic observation was used to identify the morphological changes in endothelial progenitor cells and measure the cell count. Results Adherent cells and early CFUs in groups LLTL, LH and LHTL increased more obviously than in group LL(P0.05). Conclusion Proliferative capacity of endothelial progenitor cells can be promoted by both hypoxic stimulation and exercise, and the promotion is more significant if combination of hypoxia and exercise was employed simultaneously.
ABSTRACT
OBJECTIVE: As a new method of altitude training, stimulated living high-training low training (HiLo), can solve the problems in traditional altitude training. In this paper, we review the effect of simulated living high-training low on the related indexes of red blood cells and the expression of erythropoietin and hypoxia inducible factor-1mRNA to improve the development and application of HiLo, and make it better service for our athletes. DATA SOURCES: A computer-based online search of PubMed was undertaken for the articles published between January 1972 and December 2005, among which partial articles were retrieved according to relevant references with the keywords of "simulated living high-training low training (HiLo), indices of red blood cell, effect; erythropoietin, hypoxia inducible factor-1; gene". Meanwhile, we searched http://cnki.hunnu.edu.cn for the relevant articles published between 1996 and 2006 with the same key words in Chinese. STUDY SELECTION: The articles that involved the effect on the indices of red blood cell and the expression of erythropoietin and hypoxia inducible factor-1 mRNA in the model of stimulated living high-training low training through the first trial sport were chosen after the first selection. Then, the full texts of these articles were looked up to identify whether they were the relevant studies. Inclusive criteria: ①randomised controlled experiments; ②the experiment including control and intervention groups. Exclusive criteria: ①review articles; ②repetitive studies. DATA EXTRACTION: Totally 90 relevant articles were collected, of which 38 were accordant with the inclusive criteria and the 52 repetitive studies or review articles were excluded. DATA SYNTHESIS: ①Levine discovered that in HiLo the maximal O2 consumption (VO2max) in the training group was increased 5% in the mean and red cell 9% and the ability of exercise was largely improved, while the results of the control group had no significant changes. ②HiLo training can induce the production of hypoxia inducible factor-1, which regulates erythropoietin, and its production. The increase in erythropoietin triggers an increase in red cell mass and Hb concentration. This hematological acclimatization response facilitates the restoration of blood O2 content and improves tissue oxygenation. Continuous residence at moderate heights (over 2 000-2 500 m) could improve the oxygen transport capacity, augment VO2 max and enhance exercise performance by increasing the content of erythropoietin and hemoglobin concentration. ③HiLo can induce the expression of hypoxia inducible factor-1, but the problems that how it regulates the expression of erythropoietin and transport the signal, and HiLo can alert the portion of blood, which affects the ability of exercise still need further study. Then we will more clearly learn the mechanism of the effect of HiLo on the ability of athletes, and help to enhance their performance. CONCLUSION: HiLo can increase the expression of erythropoietin and hypoxia inducible factor-1mRNA and the generation of red blood cells, which leads to an increase in hemoglobincon concentration and hematocrit, and effectively improves the ability of athletes.