运动干预对衰老模型大鼠血清炎性因子水平的影响

目的:探讨6周跑台运动对D-半乳糖致衰老模型大鼠血清炎性因子水平的影响,以此阐明运动延缓衰老的部分机制。方法:将雄性SD大鼠随机分为正常对照组(NC组)、衰老对照组(AC组)、衰老训练组(AE组),每组8只。AC和AE组大鼠每日腹腔注射1次D-半乳糖125 mg/kg,NC组注射等量生理盐水,持续6周。同时,AE组进行6周中小强度跑台训练。6周后,各组大鼠腹主动脉取血,分离血清检测血清中白细胞介素-6(IL-6)、白细胞介素-10(IL-10)、肿瘤坏死因子-α(TNF-α)的含量。结果:与正常对照组比较,衰老模型组大鼠血清IL-6、TNF-α水平明显升高(P＜0.01);与衰老模型组比较,衰老训练组大鼠血清IL-6、IL-10和TNF-α水平明显减少(P＜0.01),表明6周中小强度跑台训练有助于降低衰老机体促炎症因子的分泌,减弱体内炎症反应。结论:6周中小强度跑台训练在一定程度上可以纠正衰老机体内的炎性因子网络紊乱状况,起到干预炎性衰老的目的。     

Ammonia production following maximal exercise: treadmill vs. bicycle testing.

From a population of 20 healthy male volunteers, half performed constant speed, incremental load maximal aerobic capacity (VO2max) tests on a motor-driven treadmill, while the other half performed similar VO2max tests on a bicycle ergometer. The two groups, matched for size and age, showed no significant differences in VO2max, maximum heart rate, or in post-exercise (4 min ) peripheral venous blood concentrations of lactete or pyruvate. However, post-exercise peripheral venous blood ammonia levels were significantly higher in the group tested on the bicycle ergometer than in the treadmill group.     

Effect of treadmill exercise on bone mass in female rats.

Increasing peak bone mass at skeletal maturity, minimizing bone loss during middle age and after menopause, and increasing bone mass and preventing falls in advanced age are important measures for preventing osteoporotic fractures in women. Exercise has generally been considered to have a positive influence on bone health. This paper reviews the effects of treadmill exercise on bone in young, adult, ovariectomized, and osteopenic female rats. Treadmill exercise increases cortical and cancellous bone mass of the tibia as a result of increased bone formation and decreased bone resorption in young and adult rats. The increase in lumbar bone mass seems to be more significant when long-term exercise is applied. Treadmill exercise prevents cancellous bone loss at the tibia as a result of suppressed bone resorption in ovariectomized rats, and increases bone mass of the tibia and mechanical strength of the femur, as a result of suppressed bone resorption and increased bone formation in osteopenic rats after ovariectomy. Treadmill exercise transiently decreases the serum calcium level as a result of accumulation of calcium in bone, resulting in an increase in serum 1,25-dihydroxyvitamin D(3) level and a decrease in serum parathyroid hormone level. We conclude that treadmill exercise may be useful to increase bone mass in young and adult rats, prevent bone loss in ovariectomized rats, and increase bone mass and bone strength in osteopenic rats, especially in the long bones at weight-bearing sites. Treadmill exercise may have a positive effect on the skeleton in young, and adult, ovariectomized, and osteopenic female rats.     

Effect of treadmill exercise on plasma and urinary cyclic adenosine 3'5'-monophosphate.

The effect of treadmill exercise on plasma and urinary cyclic adenosine 3'5' monophosphate levels (cyclic AMP) was studied in twelve healthy subjects. Plasma cyclic AMP levels were found to be markedly elevated without significant changes in urinary cyclic AMP or cyclic AMP/creatine ratio. Most likely altered plasma glucagon and catecholamine levels were responsible for these changes.     

Metabolic effects of treadmill exercise training on the diabetic heart.

This study determined whether exercise training in rats would prevent the accumulation of lipids and depressed glucose utilization found in hearts from diabetic rats. Diabetes was induced by intravenous streptozotocin (60 mg/kg). Trained diabetic rats were run on a treadmill for 60 min, 27 m/min, 10% grade, 6 days/wk for 10 wk. Training of diabetic rats had no effect on glycemic control but decreased plasma lipids. In vivo myocardial long-chain acylcarnitine, acyl-CoA, and high-energy phosphate levels were similar in sedentary control, sedentary diabetic, and trained diabetic groups. The levels of myocardial triacylglycerol were similar in sedentary control and diabetic rats but decreased in trained diabetic rats. Hearts were perfused with buffer containing diabetic concentrations of glucose (22 mM) and palmitate (1.2 mM). D-[U-14C] glucose oxidation rates (14CO2 production) were depressed in hearts from sedentary diabetic rats relative to sedentary control rats. Hearts from trained diabetic rats exhibited increased glucose oxidation relative to those of sedentary diabetic rats, but this improvement was below that of the sedentary control rats. [9,10(-3)H]palmitate oxidation rates (3H2O production) were identical in all three groups. These findings suggest that exercise training resulted in a partial normalization of myocardial glucose utilization in diabetic rats.     

Effect of regular voluntary exercise on resting cardiovascular responses in SHR and WKY pregnant rats.

The purpose of this study was to assess the influence of regular voluntary exercise in pregnant normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats on 1) uteroplacental perfusion and mean arterial pressure in the resting conscious condition and 2) fetal number, fetal weight, and number of fetal resorptions. WKYs and SHRs were randomly assigned to standard cages [CWKY (n = 10); CSHR (n = 6)] or cages with activity wheels [EWKY (n = 7); ESHR (n = 8)]. EWKYs and ESHRs exercised for 12 wk, and then all rats were bred and experiments were conducted on gestational day 17. Resting blood flow (microspheres), heart rate (HR), and mean arterial pressure (Pa) were measured. No significant difference was found in Pa, HR, uterine blood flow (ESHRs 52 +/- 8 ml.min-1.100 g-1; CSHRs 28 +/- 6 ml.min-1.100 g-1), or maternal placental blood flow (ESHRs, 122 +/- 31 ml.min-1.100 g-1; CSHRs 78 +/- 21 ml.min-1.100 g-1) among the groups. Exercise altered the relationship between maternal placental and uterine blood flow and Pa in the SHR; SHRs with lower Pa maintained higher placental and uterine blood flow after training. Before gestation ESHRs ran on average more kilometers per week than EWKYs (43 +/- 3 vs. 34 +/- 4), but during gestation ESHRs averaged fewer kilometers per week than EWKYs (16 +/- 4 vs. 22 +/- 4). Succinate dehydrogenase activity was higher in the white vastus lateralis (1.02 +/- 0.2 mumol cytochrome c reduced.min-1.g wet wt-1) and vastus intermedius (3.1 +/- 0.5 mumol cytochrome c reduced.min-1.g wet wt-1) muscles of ESHRs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic value of maximal treadmill exercise electrocardiogram in predicting coronary artery disease for asymptomatic Chinese male subjects

The value of maximal treadmill exercise electrocardiogram (TEE) in predicting coronary artery disease was evaluated in a consecutive series of 168 asymptomatic Chinese males, aged 41 to 57 years (mean 53) during annual physical examinations. Their resting electrocardiograms (ECGs) showed no abnormal Q-waves. The end-point of TEE achieved the age-predicted maximal heart rate, and no subjects had classic angina pectoris during or after TEE. Thirty-five subjects had positive electrocardiographic changes defined as reversible horizontal or downsloping ST-segment depression greater than or equal to 1.0 mv which lasted greater than or equal to 0.08 sec. Exercise thallium-201 (T1-201) myocardial imaging was performed on all 35 subjects with positive TEE; 30 subjects (86%) demonstrated normal and 5 abnormal scintigrams. Sixteen of the 30 cases with normal T1-201 scans underwent coronary arteriography, of which 14 showed normal arteriograms and two showed a less than 49% stenosis of the luminal diameter in one major artery. Of the 5 cases with abnormal scintigrams, 4 were found to have greater than 50% stenoses in at least one major artery, and only one case had a less than 49% stenosis of the right coronary artery. We concluded that TEE alone for asymptomatic individuals provided limited value in diagnosing significant coronary artery disease, especially in areas of low prevalence.     

Effect of exercise training on antioxidant enzymes and cardiotoxicity of doxorubicin

The purpose of this study was to correlate the exercise-induced changes of oxidant stress enzymes with possible modification of the response to the putative oxidant stressor doxorubicin. Enzymatic and histological changes were studied in mice placed on a 21-wk swim training program (1 h/day, 5 days/wk) with and without anthracycline administration. Doxorubicin (4 mg/kg) was administered intravenously through a tail vein on 10 separate days over a 7-wk period (twice weekly during weeks 10, 11, 14, 15, and 16). Blood, liver, and heart levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GP) were measured following the 9th and 21st wk. Myocardial histomorphological observations were made by light microscopy after 21 wk. Following 9 wk of training swim-trained animals had significantly elevated levels of CAT, SOD, and GP in blood, as well as elevated GP in liver. After 21 wk, trained animals, regardless of drug status, had elevated blood CAT and SOD activity and increased liver CAT and GP. Training also produced increases in blood GP, liver SOD, and heart CAT; however, in conjunction with doxorubicin these changes were not seen. The degree of cardiotoxicity was significantly greater in the sedentary drug-treated animals than in the swim-trained drug-treated animals. The results suggest a correlation between antioxidant enzyme levels in blood and liver and the degree of damage caused by an anthracycline drug. It was concluded that exercise ameliorates severe toxic damage caused by doxorubicin administration, possibly by increasing enzymes that combat free radical damage.     

Effect of exercise on glycolytic enzymes of zucker fatty rats

Summary The effect of fatigue (running to exhaustion) on the Vmax activity of the key glycolytic enzymes measured at saturating substrate concentrations in muscles, liver and brain of sedentary and trained (running on a treadmill one h/day at 20 m/min, five days/week for six months) female Zucker fatty rats and their lean littermates was investigated. In the sedentary rats, fatigue increased the activity of phosphofructokinase (PFK) in the red vastus muscle by 82% in lean, and 120% in obese rats. In the trained rats, fatigue increased PFK activity by 28% in the white vastus muscle of lean rats. In the lean animals, hexokinase (HK) activity was decreased by 26% in the red vastus of sedentary rats, and by 29% in the white vastus of trained rats upon fatiguing. Pyruvate kinase (PK) activity was also decreased by 29% in the white vastus of fatigued lean animals. Training by itself had no effect on the activity of glycolytic enzymes, except PK activity which was increased by 27% in the cortex of the lean animals. It is concluded that in the Zucker rat, these glycolytic enzymes may play a differential role in regulating glycolysis during exercise and fatigue; the extent of their involvement differs depending upon the type of tissue studied and exercise. In view of the reported short half-life (7–17 h) of PFK and its covalent modification, it is suggested that the total content and/or phosphorylation status of the enzyme may be affected in animals subjected to long-term fatigue.Abbreviations PFK Phosphofructokinase (EC 2.7.1.11) - PK Pyruvate Kinase (EC 2.7.1.40) - HK Hexokinase (EC 2.7.1.1) - LSC Lean Sedentary Control - LTC Lean Trained Control - LSF Lean Sedentary Fatigued - LTF Lean Trained Fatigued - OSC Obese Sedentary Control - OTC Obese Trained Control - OSF Obese Sedentary Fatigued - OTF Obese Trained Fatigued     

Effect of exercise on mRNA expression of select adrenal medullary catecholamine biosynthetic enzymes.

The effect of submaximal endurance training (SET) on sympathoadrenal activity is not clear. We tested the hypothesis that SET (90 min/day, 5 days/wk, for 12 wk) elevates mRNA expression of catecholamine (CA) biosynthetic enzymes, tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DbetaH) in the adrenal medullae of adult, female Sprague-Dawley rats. SET increased TH protein level by 35%, TH activity by 62%, TH mRNA expression by 40%, and DbetaH mRNA expression by 67%. In addition, we examined the effect of SET on Fos-related antigens (FRAs), FRA-2 immunoreactivity, and activator protein (AP)-1 binding activity. SET increased AP-1 binding activity by 78%; however, it did not affect late FRAs and FRA-2 immunoreactivity. Because the regulation of neuropeptide Y (NPY) often parallels that of CAs, we also examined the effect of SET on NPY mRNA expression. Indeed, SET elevated NPY mRNA expression as well. We conclude that 1) SET elicits a pretranslational stimulatory effect on adrenomedullary CA biosynthetic enzymes, 2) another immediate early mRNA product, rather than FRA-2, may contribute to the increase in AP-1 binding activity in response to SET, and 3) SET increases NPY mRNA expression.