Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a marker of oxidative stress in rheumatoid arthritis and aging: effect of progressive resistance training

Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG), as a measure of oxidative stress, was measured before and after 12 weeks of progressive resistance strength training in 8 healthy elderly (65–80 yr) and eight healthy young (22–30 yr) men and women, and in eight adults (25–65 yr) with rheumatoid arthritis (RA).Training subjects exercised at 80% of their one-repetition maximum and performed eight repetitions per set, three sets per session, on a twice-weekly basis. 8-OHdG was measured at baseline and follow-up (at least 24 hr after the last exercise session) in the RA and elderly subject groups, and at baseline only in young subjects.Baseline 8-OHdG levels were greater among subjects with RA compared to both healthy young (P < 0.001) and elderly (P < 0.05) subjects. There were no changes in 8-OHdG levels in either RA or elderly subjects as a result of the strength training intervention.These results suggest that subjects with RA have higher levels of oxidative stress than young and elderly healthy individuals. Furthermore, there is no change in oxidative stress, measured by urinary 8-OHdG, in elderly healthy individuals or in subjects with RA after a 12-week strength training intervention.     

Effect of polar glycopeptidolipids from Mycobacterium Chelonae (GPLp-Mc) on phagocytosis and superoxide anion production of macrophages from mice. Influence of physical activity

It is not clear how macrophages respond to exercise when the immune system is previously activated. The aim of the present work was to determine the response of macrophages to exercise in already immunostimulated animals with polar glycopeptidolipids extracted from Mycobacterium chelonae (GPLp-Mc). Results showed an increased phagocytosis and O₂ ^- production in murine macrophages induced by the intraperitoneal administration of 25 mg/kg body weight of GPLp-Mc. In addition exercise stimulated phagocytic activity and decreased the O₂ ^- production of these cells. Unexpectedly, exercise did not potentiate the immunostimulatory effect of GPLp-Mc. However, we can conclude that the effect of exercise is not detrimental to immunostimulated animals.     

Acute hormone responses to heavy resistance lower and upper extremity exercise in young versus old men

Acute hormone responses of growth hormone (GH), total and free testosterone (TT and FT) and cortisol (C) to heavy resistance isometric exercise were examined in ten young men [YM 26.5 (SD 4.8) years] and ten old men [OM 70.0 (SD 3.7) years]. Loading conditions of the same relative intensity were created for the lower and upper extremity actions separately as well as for both of them together – lower extremity exercise (LE; knee extension), upper extremity exercise (UE; bench press extension), and lower and upper extremity exercise (LUE) performed simultaneously in a seated position. Single voluntary maximal isometric actions lasting for 5 s were performed repeatedly for ten repetitions (with a recovery of 5 s) for a total of four sets. The recovery time between the sets was 1 min. Each exercise led to large acute decreases in maximal isometric force in both YM (P < 0.001) and OM (P < 0.001) ranging from 41% to 26% with no significant differences between the groups. Serum GH concentrations increased in both YM (P < 0.05–0.01) and OM (P < 0.05) but the postexercise value in YM during LE was greater (P < 0.05) than for OM. The TT increased (P < 0.01–0.001) in YM in all three exercises, while in OM the increase occurred only during LE (P < 0.01). The exercises led to increases in FT in YM (P < 0.05 for LE and LUE), while in OM the increase occurred only during LUE (P < 0.05). The pre and postexercise FT were greater in YM (P < 0.001) than in OM. No significant changes occurred in C either in YM or in OM. The blood lactate concentrations increased during the exercises in both YM (P < 0.001) and OM (P < 0.05–0.001) but the postexercise values during LE and LUE in YM were greater (P < 0.05) than in OM. The present data would indicate that the responses of GH, TT and FT to heavy resistance isometric exercise are lowered with increasing age. The reduced acute hormone response together with the lowered basal values in FT in the older men compared to the young men may indicate decreased anabolic effects on muscles and may explain in part the loss of muscle mass and strength associated with aging. Accepted: 18 August 1997     

A comparison of physiological responses and rating of perceived exertion between high-impact and low-impact aerobic dance sessions

The aim of this study was to compare the exercise intensity and rating of perceived exertion (RPE) of a high-impact (HIP) and a low-impact (LIP) university aerobic dance session. Ten women [mean (SD) age 22.9 (2.6) years] took part in the study. An incremental treadmill test was performed by each subject to determine maximum oxygen consumption (V˙O_{2 max} ) and maximum heart rate (HR _max ). The measured V˙O_{2 max} [mean (SD)] was 49.0 (7.5) ml · kg⁻¹ · min⁻¹. The subjects were randomly assigned to LIP and HIP sessions (i.e. five of the subjects participated in the HIP session first, and the other five participated in the LIP session first). In a laboratory, heart rate, oxygen uptake and RPE were measured throughout each session for each subject. Expired air was collected continuously throughout the sessions using Douglas bags (ten bags over a 30-min period). The sessions consisted of 20 min of aerobic exercise (bags 1–7) followed by 5 min of local muscular endurance exercise (bags 8 and 9) and 5 min of flexibility exercises (bag 10). The mean intensity of the aerobic section of the LIP and HIP sessions was 51.6% and 64.7% V˙O_{2 max} , respectively. Ninety-five percent confidence intervals for the average difference between the HIP and LIP sessions demonstrate that the %V˙O_{2 max} was between 12% and 14% higher for the HIP session. The mean %HR _max for the LIP and HIP sessions was 71.4% and 76.7%, respectively, with the %HR _max in the HIP session being between 5.4% and 7.2% higher on average than that of the LIP session. On average, the RPE for the aerobic section of the HIP session (12.1) was consistently higher than that of the LIP session (11.1). HIP activity has the potential to maintain/improve the aerobic fitness of its participants. According to the literature, the exercise intensity elicited by LIP activity may have a limited training effect for the population utilised in this study, and for some individuals may result in detraining. Conversely, LIP activities may be an appropriate mode of exercise for overweight and unfit individuals. Accepted: 5 January 1998     

Effects of repetitive dynamic contractions upon electromechanical delay

The effect of repeated maximal effort isotonic contractions on electromechanical delay was studied. Over 4 days, 17 male subjects performed 400 rapid elbow flexion trials. The kinematics and surface electromyographic (EMG) activity of the biceps brachii of these subjects were recorded. The period from the onset of the EMG until the beginning of movement was defined as the electromechanical delay. The period from the beginning of movement until the end of the EMG was defined as the second component of the contraction. Over the 4 day period there was an increase in the speed of limb movement. The mean power frequency and the duration of the EMG during the electromechanical delay did not change, while the root-mean-square amplitude increased. The duration of the EMG during the second component of the contraction remained stable. The mean power frequency and the root-mean-square amplitude of the EMG during the second component of the contraction increased with the speed of limb movement. We conclude that the faster contractions were a result of changes in motor unit recruitment during the second component of the contraction, rather than in the electromechanical delay.     

Rectal and esophageal temperatures during upper- and lower-body exercise

This study investigated the question: is core temperature measurement influenced by whether exercise involves predominantly upper- or lower-body musculature? Healthy men were allocated to three groups: treadmill ergometry (T) n=4, cycle ergometry (C) n=6 and arm crank ergometry (AC) n=5. Subjects underwent an incremental exercise test to exhaustion on an exercise-specific ergometer to determine maximum/peak oxygen consumption (V˙O_2max). One week later subjects exercised for 36 min on the same ergometer at approximately 65% V˙O_2max while temperatures at the rectum (T _re) and esophagus (T _es) were simultaneously measured. The V˙O_2max (l · min⁻¹) for groups T [4.76 (0.50)] and C [4.35 (0.30)] was significantly higher than that for the AC group [2.61 (0.24)]. At rest, T _re was significantly higher than T _es in all groups (P<0.05). At the end of submaximal exercise in the C group, T _re [38.32 (0.11)°C] was significantly higher than T _es [38.02 (0.12)°C, P<0.05]. No significant differences between T _re and T _es at the end of exercise were noted for AC and T groups. The temperature difference (T _diff) between T _re and T _es was dissimilar at rest in the three groups; however, by the end of exercise T _diff was approximately 0.2°C for each of the groups, suggesting that at the end of steady-state exercise T _re can validly be used to estimate core temperature. Accepted: 3 November 1997     

Hypothalamic-pituitary-adrenal and -gonadal axis function after exercise in sedentary and endurance trained elderly males

The aim of this study was to investigate hypothalamic-pituitary-adrenal (HPAA) and -gonadal (HPGA) axis responses to post-exercise (30 min at 65% V˙O_2max) combined corticotrophin, luteinizing hormone and thyrotrophin releasing hormone challenge (0.7 μg/kg body mass) in elderly distance runners (DR; age: 68.9 ± 4.2 year) and sedentary individuals (SI; age: 69.1 ± 2.6 year). Plasma cortisol, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone and total testosterone (T) concentrations pre- and post-exercise as well as in response to stimulation did not differ between DR and SI. Plasma adrenocorticotropic hormone returned to pre-exercise level in DR 60 min and in SI 90 min post-stimulation. Free T was lower in DR at all time points. Our results do not support the notion of altered releasing hormone-stimulable HPAA and HPGA synthesis-secretion capacity in elderly males after endurance training. Accepted: 18 November 1997     

模拟不同海拔高度训练对大鼠红细胞变形性的影响

本研究用红细胞最大变形指数,血红蛋白浓度,血球压积等指标,以雄性ＳＤ大鼠为实验对象,观察了低压氧舱模拟不同海拔高度的训练对鼠ＲＢＣ变形性的影响。     

Familial Aggregation of Amount and Distribution of Subcutaneous Fat and Their Responses to Exercise Training in the HERITAGE Family Study

Objective: Investigate the familial aggregation of amount and distribution of subcutaneous fat and their changes in response to endurance training. Research Methods and Procedures: A total of 483 sedentary subjects from 99 nuclear families were recruited, trained for 20 weeks of exercising on cycle ergometers, and measured before and after training for the following indicators of subcutaneous fat and fat distribution: trunk fat (TRUNK = sum of abdominal, subscapular, suprailiac, and midaxillary skinfolds), extremity fat (EXTREM = sum of biceps, triceps, thigh, and calf skinfolds), subcutaneous fat (SF8 = sum of the eight skinfolds), the trunk to extremity skinfolds ratio adjusted for SF8 (TER) and waist girth adjusted for body mass index (WAIST). The familial aggregation of the age‐ and sex‐adjusted baseline phenotypes and their responses to training (Δ) after adjustment for the baseline values was investigated using a familial correlation model. Results: Significant familial aggregation was observed for all the phenotypes measured at baseline and for ΔTRUNK and ΔWAIST. Transmissibility estimates reached about 30% to 35% for TRUNK, EXTREM, and SF8 and 50% for TER and WAIST. The transmissibilities of the response phenotypes were lower, ranging from 0% for ΔWAIST to 21% for ΔTRUNK and the pattern of familial correlations suggested a greater within‐ than between‐generation resemblance in the response. Discussion: This study suggests that the amount and distribution of subcutaneous fat strongly aggregates in families, whereas the response to exercise training is characterized by a moderate and more complex pattern of familial resemblance. We conclude that familial/genetic factors are more important in determining the amount and distribution of subcutaneous fat than their responses to exercise training.     

运动干预对肥胖大鼠睾丸自噬和凋亡的影响

目的 探讨肥胖对大鼠生精小管结构及自噬和凋亡相关蛋白质的影响,并探讨运动对睾丸自噬和凋亡的影响及其调控机制。方法 将50只6周龄雄性SD大鼠随机分为标准饲养组（SD组,n=20）和高脂饲养组（HFD组,n=30）。HFD组喂养8周建立肥胖大鼠模型,并随机筛选出20只肥胖大鼠进行运动干预。SD组和HFD组分别随机分为标准对照组（CC组）、标准运动组（CE组）、肥胖对照组（OC组）、肥胖运动组（OE组）,每组10只。其中CE组和OE组进行8周中等强度跑台运动干预,60 min/d,5 d/周,其他两组维持原饲养条件。在最后一次运动结束48 h后,将大鼠腹腔麻醉,称重,取大鼠左右两侧睾丸、称量睾丸重量并计算睾丸指数。制作睾丸石蜡切片,利用HE染色法观察睾丸组织结构。采用蛋白质印迹法（Western blot）检测睾丸组织中p62、LC3II、LC3I、BCL-2、Bax和AMPK蛋白表达量并计算LC3II/LC3I比值,采用免疫荧光检测睾丸中LC3和BCL-2蛋白表达位置。结果 与CC组相比,OC组大鼠睾丸指数降低,生精小管直径显著降低（P<0.01）,精子细胞减少,睾丸组织中有脂滴沉...