ABSTRACT
Aim To study the effects of HiHi and HiLo on the lipid metabolism in rats through blood lipids and fatty acid oxidation in gastrocnemius of rats. Methods Thirty male SD rats were selected by means of adaptive training, and then divided into 3 groups randomly: living low-training low group (LoLo), living high-training high group (HiHi), and living high-training low group (HiLo). The rats ran on a treadmill 60 min a day at the speed of 35 m/min under normoxic condition or 30 m/min under hypoxic condition (13.6% of ambient FIO_2), 6 days a week for 4 weeks. The samples from blood and gastrocnemius were removed 24 hours after the last training by the end of 4-week experiment. TC, TG, HDL and LDL were tested with a full-automatic biochemical analyzer. LPL, leptin and AD were measured using ELISA. Real-time quantitative PCR was adopted to test the expression of PPARa and CPT-1 mRNA in rats' gastrocnemius. Results Compared to the LoLo, TC and TG decreased significantly (P0.05) and LPL and AD increased significantly (P<0.01) in HiHi.' PPARa mRNA and CPT-1 mRNA expressions in gastrocnemius were significantly higher in HiHi(P<0.05) than in LoLo, and significant descent of HDL(P<0.05) and CPT-1 mRNA expression(P<0.01) revealed in HiLo, as compared to the LoLo. Compared to the HiLo, HDL(P<0.05), and LPL, AD and CPT-1 mRNA expression(P<0.01) enhanced in HiHi. Conclusion (l) HiHi was more superior in regulation of blood lipids than LoLo due to increasing of LPL, and could facilitate fatty acid oxidation because of enhancement of CPT-1 mRNA, AD and PPARa mRNA. (2) Comparing to the normoxic training, HiLo had no beneficial effect on the blood lipid metabolism and decreased the fatty acid oxidation in gastrocnemius.(3 )HiHi was more superior in the effeet of HDL thah HiLo due to increasing of LPL, and could facilitate fatty acid oxidation because of enhancement of AD and CPT-1 mRNA.
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
This study was to investigate the influnce of 4 weeks of living high-training low on exercise performance of rowers. Twenty rowers were divided into two groups: ten subjects spent 8-10h per night in a tabernacle simulated at an altitude of 2500m in normobaric hypoxia; 10 control subjects slept at near sea level. During the 4-week periods, all rowers were trained at the same relative or at the same intensity of work in normoxia state. The red cell volume (RCV) , haemoglobin mass (Hb) and hematocrit (HCT) were measured before test, 15th and 30th day of study,and measurements were done on a rowing ergometer at sea-level, which included an ergometer test at 4 mmol/L lactate anaerobic threshold and performance in exercise tasks of 2km, 5km, and a Wingate Anaerobic Test before test and 30th day of study. The results showed that adaptation to simulated moderate altitude can stimulate red cell production sufficiently: increase in red cell volume (RCV) , haemoglobin mass (Hb) and hematocrit (Hct). And there were significant increases in all important parameters at 4 mmol/L lactate anaerobic threshold as well as performance of 5km, while the performance of 2km showed no significant improvement, the mean values of both mean power per kilogram body weight and peak power per kilogram body weight were not increased significantly. In the control group, there were no significant changes in the all abovementioned parameters. The results of this study indicate that living high-training low can improve the aerobic energy-supply systems. We conclude that 4-week of living high and training low can improve sea level endurance performance in rowers.