Time course of haemodynamic changes after maximal exercise

Abstract. The haemodynamic changes during 4 h following maximal upright bicycle exercise were evaluated in six normals in a randomized controlled crossover design. Total peripheral resistance was reduced to 2 h (-6·7 mmHgmin l^-1, P < 0·05); exercising and non-exercising vascular beds were vasodilated for 2h (-24·1 and -23·8 mmHg min ml^-1 100ml^-1 tissue, respectively, P < 0·05), associated with reductions in systolic (-5·8 mmHg, P < 0·05) and diastolic pressure (-8·3mmHg, P < 0·05). Rise in cardiac index for 1 h (+0·51min^-1 m^-2, P < 0·05) was accounted for by an elevated heart rate (+14·4 beats min^-1, P < 0·01) as stroke volume was unchanged. Body temperature was elevated until 40min (+0·20°C, P < 0·05). The return of all haemodynamic variables to control by 3h suggests a 3 h limit for a hypotensive effect of exercise. Rise in body temperature is not the only factor responsible for the hypotension.     

Time course of changes in pancreatic enzymes, isoenzymes and, isoforms in serum after endoscopic retrograde cholangiopancreatography.

Kinetics of the catalytic activities of total amylase (AMY; EC 3.2.1.1), pancreatic (P)-AMY isoenzyme, P2 and P3 isoforms, and pancreatic lipase (LPS; EC 3.1.1.3), and of the mass concentration of LPS in serum were studied in 10 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) and showed a distinct pancreatic injury. The temporal characteristics of enzyme changes described were (a) the maximal rate (Ka) at which enzymes are released into blood, (b) the time lag from ERCP until maximum concentration value, (c) the peak value of each serum enzyme, and (d) the rate (Kd) at which each enzyme is cleared from serum. LPS activity and mass concentrations increased and decreased faster than AMY and isoamylases, and the time of the LPS peak tended to be earlier than that of the other enzymes, but not significantly. The average peak increase of LPS values was higher than that of total AMY, P-AMY, and P2 isoform (P less than 0.001). The P-AMY time-activity curve was a composite of curves attributable to its isoforms; the isoforms increased and peaked sequentially, with P3 returning to normal more slowly than did P2. LPS mass and activity concentrations showed excellent parallelism, with no important differences. At 50 h after ERCP, only LPS values still exceeded the upper reference limit, returning to normal 70 h after the examination.     

Variation of serum and urinary neutrophil gelatinase associated lipocalin (NGAL) after strenuous physical exercise

Abstract Background: Strenuous exercise may trigger acute complications, such as exertional rhabdomyolysis and gastrointestinal complaint. As less is known about the potential renal impairment after long distance running, we assessed creatinine and neutrophil gelatinase associated lipocalin (NGAL) in serum (sNGAL) and urine (uNGAL) before and after an ultramarathon. Methods: The study population consisted of 16 trained male athletes who ran a 60 km ultramarathon. Blood and spot urine samples were collected 20 min before and immediately after the run. Creatinine was assessed by Jaffe assay on Beckman Coulter AU5800 and renal function was expressed as estimated glomerular filtration rate (eGFR) by MDRD formula. NGAL was measured by fully-automated immunoassay NGAL Test? on AU 5800. Results: Serum and urinary creatinine increased significantly by 38% and 78%, respectively. The eGFR contextually decreased by 31%. sNGAL, uNGAL and uNGAL/creatinine ratio increased by 1.6-fold, 7.7-fold and 2.9-fold. In six of 16 athletes (38%), the acute post-exercise increase of serum creatinine met the criteria of acute kidney injury. No significant relationship was found between pre-exercise, post-exercise values and post-exercise variation of sNGAL, uNGAL and uNGAL/creatinine ratio. A significant correlation was found between pre- and post-exercise changes of serum creatinine and sNGAL, but not with either uNGAL or uNGAL/creatinine ratio. Conclusions: The acute variations of serum creatinine and uNGAL attest that renal impairment is likely to develop after long distance running. The uNGAL seems more independent from creatinine variation and extra-renal sources, and thereby more reliable for monitoring the renal involvement in these types of kidney impairment.     

Influence of strenuous exercise on albumin excretion

Renal albumin excretion rate was 7.3 mg/24 h (SEM 0.5, range 0.6-21.0) in 66 healthy subjects. This rate increased markedly during and shortly after strenuous exercise on a bicycle ergometer (before: 5.5 +/- 0.6 micrograms/min; during and just after: 16.9 +/- 2.2 micrograms/min; P less than 0.001; n = 30). However, albumin excretion/24 h was not significantly higher during 24 h with a period of strenuous exercise than during 24 h without such exercise (10.3 +/- 0.9 mg/24 h vs 8.5 +/- 0.7 mg/24 h).     

Change in concentrations of myogenic components of serum during 93 h of strenuous physical exercise

Effects of 93 h of long, strenuous ranger training on activities of creatine kinase (CK) and lactate dehydrogenase (LD), along with their isoenzymes, and on concentration of myosin light chain were examined in sera of young soldiers. Total CK activity in serum was measured before, during, and after the training. Throughout, total CK activity in serum increased steadily. At the end of the training, activity of CK-MB was increased but its activity ratio to total CK remained unchanged; the activity ratio of LD1/LD2 also was not increased, although total LD activity was increased. Myosin light chain was increased by about fourfold at the end of the training and remained high for three days thereafter. However, its concentration was much lower than in myopathies such as polymyositis and Duchenne muscle dystrophy. The increased activities in serum of total CK and CK-MB isoenzyme on strenuous physical exercise evidently were of noncardiac origin. Although CK activity was comparable with that seen in myopathies accompanied by disintegration of skeletal muscle, the relatively low concentration of myosin light chain in serum suggests minimal skeletal muscle damage.     

Effect of manual lymph drainage on the course of serum levels of muscle enzymes after treadmill exercise

OBJECTIVE: Improving muscular recovery after exercise is an important topic in sports medicine. The aim of the present study was to evaluate the effect of manual lymph drainage on the course of serum levels of muscle enzymes after an extended treadmill exercise. DESIGN: Fourteen recreational athletes (seven women, seven men) were included in the study. The participants underwent a graded exercise test on a treadmill ergometer to determine the individual anaerobic threshold (IAT). Seven days after the graded exercise test, all subjects performed 30 mins of treadmill exercise at an intensity equivalent to IAT. The subjects were randomized into two groups of seven persons. One group was treated with manual lymph drainage (ML), whereas the control group (CG) received no treatment after the endurance exercise at IAT level. RESULTS: After an increase immediately after exercise, a fast decrease in lactate dehydrogenase (LDH) and in aspartate aminotransferase (AST) concentration was observed, with significantly lower values for LDH after 48 hrs in the subjects having received lymph drainage treatment. The course of creatine kinase (CK) levels was comparable, but did not reach significance. CONCLUSION: Manual lymph drainage after treadmill exercise was associated with a faster decrease in serum levels of muscle enzymes. This may indicate improved regenerative processes related to structural damage of muscle cell integrity.     

Flow changes in forearm arteries after elevating the radial forearm flap: prospective study using color duplex imaging.

The aim of the present study was to assess the changes in flow patterns of forearm arteries produced by excision of the radial artery when harvesting the radial forearm flap. A prospective study using color duplex imaging for quantitative flow measurements was accomplished in 11 patients. After raising the radial flap, the forearm flow tended to increase overall, the ulnar (P = 0.04), the posterior interosseous (P = 0.003), and the anterior interosseous (P = 0.003) arteries being responsible for this tendency. Therefore, harvesting of a radial flap must not be considered as causing vascular morbidity in terms of blood supply to the hand.     

兔膝关节软骨表面形态在短时非周期大强度运动训练后的变化

目的:观察正常软骨表面的形态结构以及短时非周期大强度运动训练对关节软骨的影响。方法:实验于2001-01/09在四川省骨科医院完成。①实验动物:10～12个月龄日本大耳白兔8只,雌雄各半,体质量(3.5±0.2)kg。②实验分组:将动物分为对照组2只,训练组6只,其中训练1,2,3周各2只。③实验干预:训练组兔在电刺激笼中进行训练,训练量为20s刺激1次,刺激时间为0.2～0.5s,动物受刺激后沿刺激笼跑跳数步并转弯。训练120min/d,每组训练60min后休息20min,训练6d/周,星期日休息,分别训练1,2,3周。对照组不放在电刺激笼中,也不进行训练。④实验评估:扫描电子显微镜下观察训练前后兔股骨和胫骨髁软骨表面形态结构的变化;MIAS99图形处理软件计算浅坑(pits)的直径和面积。结果:8只兔均进入结果分析。①正常兔膝关节软骨的表面形态结构:正常软骨表面低倍镜下显示为均匀排列的浅坑,在高倍镜下呈现一种均匀多孔状结构。②运动训练后软骨表面结构的变化:训练后浅坑形态不规则,边缘粗糙,胶原纤维增粗,孔隙不均匀增大。结论:软骨表面正常的形态结构是浅坑,短时非周期大强度训练,未引起纤维断裂和碎屑,说明不会损伤软骨表面形态结构。     

Granulocyte margination in the human lung and its response to strenuous exercise.

1. It is widely believed that the lung is an important site of granulocyte margination and releases most of the granulocytes of the peripheral neutrophilia of exercise. 2. We measured granulocyte margination in the lung in terms of the lung total blood granulocyte pool and the lung circulating granulocyte pool in eight patients without inflammatory disease or evidence of lung pathology by comparing the regional gamma-camera lung count rate of 111In-labelled granulocytes with that of 111In-labelled erythrocytes. According to the respective 111In activities in peripheral blood samples taken between 5 and 40 min after granulocyte injection, the lung marginating granulocyte pool was 0.78 (SEM 0.045) of the lung total blood granulocyte pool or 4.6 (0.92) of the lung circulating granulocyte pool 5 min after injection, decreasing to plateau values of 0.57 (0.053) and 1.53 (0.28) from 20 min after injection. This compared with corresponding whole-body ratios of about 0.6 and 1.5, respectively. 3. After 4 min of maximal exercise in four normal subjects given 111In-labelled granulocytes 60 min before exercise, the 111In-labelled granulocyte count rate over the lung increased to 1.23 (0.05) of the pre-exercise value with a time course that was essentially identical with the time course of the peripheral native neutrophilia. The spleen 111In signal decreased with the same time course, reaching a minimum of 0.63 (0.05) of the pre-exercise level at 5-10 min after the end of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Time course of pancreatic protein synthesis following feeding

It is now well established that hormonal stimulation of the exocrine pancreas by pancreozymin and secretin results in enhanced enzyme secretion and a decrease in total protein synthesis in the early moments following application of the stimulus. The aim of the present study was to establish if the effects previously observed by these secretagogues were physiological. We thus verified the effects of feeding on pancreatic protein synthesis; data show that 45 min after a 15-min meal, protein synthesis is reduced by 18% while increases are observed at 90 and 105 min. These results indicate that the reduction in protein synthesis observed following feeding or hormonal stimulation is a physiological process.     

Time course of changes in serum oxidant/antioxidant status in overfed obese rats and their offspring

The aim of the present study was to determine the time course of changes in oxidant/antioxidant status, as well as serum glucose, insulin, leptin and lipid levels, liver adipose tissue and muscle lipid and protein contents, in cafeteria-diet-fed dams during gestation and lactation, and in their offspring throughout adulthood. Food intake was also evaluated. The cafeteria diet induced a significant increase in maternal body and relative adipose tissue weights, daily energy intake, and plasma glucose, insulin, leptin and lipid levels at parturition (day 0) and at the end of lactation (day 21). Plasma total antioxidant status [ORAC (oxygen radical absorbance capacity)], erythrocyte catalase and SOD (superoxide dismutase) activities were lower, whereas plasma hydroperoxide and carbonyl protein levels were higher in cafeteria-diet-fed mothers compared with control mothers at days 0 and 21. Pups from cafeteria-diet-fed dams, both males and females, also had consistently higher body and relative adipose tissue weights, and plasma glucose, insulin, leptin, triacylglycerol (triglyceride) and cholesterol levels at birth (day 0), weaning (day 21) and 3 months of age (day 90). These offspring had significantly lower ORAC and catalase activity, and higher plasma hydroperoxide and carbonyl protein levels and SOD activity at birth, at days 21 and 90 compared with control offspring. In conclusion, excessive maternal fat and energy intake can play an important role in the development of metabolic disorders in the offspring. Maternal oxidative stress may be among the responsible factors. Fetal oxidative stress may present an additional confounding influence and probably contributes to additional disorders, aggravating features of the metabolic syndrome. An improvement in maternal oxidant/antioxidant status during pregnancy and lactation, with adequate nutrition, could have beneficial effects on the progeny.     

Muscle metabolism during and after strenuous intermittent running.

Muscle and blood metabolites, plasma insulin and cyclic adenosine 3',5'-monophosphate (cAMP) levels were investigated in five male runners before and after strenuous intermittent running exercise of short duration. Immediately after the exercise, the mean muscle creatine phosphate level (CrP) had fallen by 74% (P less than 0.02) and 30 min later the initial level was regained in only one subject. Other immediate results were increases in mean muscle lactate (460%, P less than 0.005), glucose (130%), glucose-6-phosphate (G6P, 320%) and fructose-1,6-diphosphate (FDP, 32%). Muscle ATP and glycogen concentration had decreased by 31 and 23% (P less than 0.05), respectively. However, ATP, glucose, G6P and FDP changes were not significant owing to the great individual variation. This may have been due to the different training programmes of the runners. Immediately after the exercise mean plasma insulin was 210% (P less than 0.01), blood glucose 71% (P less than 0.005) and plasma cAMP concentration 260% (P less than 0.01) higher than the pre-exercise values. After running urinary excretion of cAMP was 29% higher than before the exercise. It is concluded that exhaustive, short-term exercise activates the liver adenylate cyclase system so giving rise to an increased level of blood glucose, which is an important source of energy during this type of exercise.     

Time course of and stimuli to compensatory growth of the lung after pneumonectomy.

Left pneumonectomy in the mature rat led to an increase of [3Ha1 thymidine incorporation into DNA of the remaining lung in the first 3 postoperative days, and resulted in a subsequent 38% increase of lung weight and 41% increase of lung tissue volume measured 1 wk after surgery. Despite these early changes, total lung volume (TLV) did not increase until the 2nd postoperative wk, reaching values 33% greater than in controls. Analysis of lung pressure-volume curves revealed that lung recoil was increased at low lung volumes 1 wk after surgery, but returned to normal by the 2nd postoperative wk, suggesting that synthesis of both lung elastin and collagen had occurred by this time. Increased inspired oxygen concentration (28% or 35%) during the 1st but not the 2nd postoperative wk abolished the change in TLV without influencing the increase in lung weight, while diminished inspired oxygen (17% or 14%) accentuated the postoperative increase in TLV. Lung pressure-volume curves demonstrated changes in distensibility at low lung volumes, suggesting that oxygen may have influenced synthesis or cross-linking of lung elastin. Alterations of minute ventilation in the postoperative period produced by 3% CO2 did not influence the compensatory growth process, nor did administration of cyclophosphamide. These studies suggest that postpneumonectomy lung growth is a two-phase process, beginning with cell proliferation and increased tissue volume, followed by increasing lung volume associated with formation of lung structural proteins. The latter process is profoundly influenced by inspired oxygen concentration in the early postoperative period.     

Time course of serum amyloid A response in myocardial infarction

Plasma concentrations of serum amyloid A (SAA), high density lipoprotein (HDL) cholesterol, non-HDL cholesterol, and apolipoproteins (Apo) A-I and B were measured daily for 6 days in 10 patients following myocardial infarction (MI) and in 10 secular controls admitted to a coronary care unit. SAA concentrations peaked 3 days following MI (mean 47 mg/dl) and correlated with creatine kinase (CK) (r = 0.67, P less than 0.001). Non-HDL cholesterol and Apo B fell 15 and 18%, respectively, reached nadirs 3-4 days after MI and were inversely related to CK concentrations (P less than 0.01 for both). HDL cholesterol levels, in contrast, increased 15% and were significantly higher than baseline by day 3 when SAA concentrations were maximum. HDL cholesterol subsequently fell in parallel with SAA and had returned to baseline by day 6. Apo A-I declined throughout the 6 days of observation and was 13% lower than initial values on day 6 (P less than 0.05). The Apo A-I reduction was inversely related to both CK and SAA concentrations. There were no significant changes in any of the analytes in control subjects. We conclude that Apo A-I and possibly Apo B containing lipoproteins are negative acute phase reactants. HDL cholesterol is transiently elevated after MI despite decreasing Apo A-I levels and this may relate to incorporation of SAA into HDL particles.     

Time course of oxidative stress after major burns

Objective: To evaluate oxidative stress resulting from major burns in humans.¶Design: Prospective clinical study with control group.¶Setting: Mechanically ventilated adult patients admitted with more than 30 % total burn surface area.¶Patients and participants: 20 patients with a mean body surface burned area of 54 %.¶Measurements and results: The oxidative stress evaluation was based on measurements of trace elements, vitamins, antioxidant enzymatic activity and end-products of lipid peroxidation. During the first 5 days after injury burn patients exhibit a decrease in selenium and antioxidant vitamins (C, β-carotene, lycopene) and an increase in lipid peroxidation products (TBARS).¶Conclusion: Our results suggest that major burn is associated with oxidative stress during the 5 days after the initial injury, as demonstrated by a simultaneous decrease in antioxidant vitamins and a large increase in TBARS.     

Time course of changes in the volume of blood cells in pregnancy

The time course of changes in the parameters of the corpuscular volume of red blood cells, lymphocytes, neutrophils, and platelets was studied during uncomplicated pregnancy. It was ascertained that in pregnancy, the mean volume of red and white blood cells and that of platelets remained steady-state. Adaptive changes were observed in the fine structure of blood cells of all types. Factor analysis demonstrated that evaluation of a system of parameter intercorrelations in the distribution of blood cells by their volume allows pregnancy phases to be clearly differentiated.     

Exercise-related time course of pulsatility index in brachial artery following forearm exercise assessed by Doppler ultrasound

At rest, vascular reactivity assessed by the changes in pulsatility index (PI) is one indicator of vessel stenosis in some clinical/basic science research. However, all types of vessel stenosis do not show an alteration in the PI, because flow perfusion may be maintained by the development of collateral vessels such as in severe arterial stenosis or non-severe arterial stenosis. Therefore at rest, changes in the PI may not always be a precise indicator of vessel stenosis. However, a few studies have used the PI following exercise, which may provide additional information on hemodynamics. The purpose of the present study was to examine the exercise-related time course of the PI in the brachial artery after ischemic or non-ischemic isometric handgrip exercise (IHE) using Doppler ultrasound, and to determine the potential use of this parameter as an indicator of vascular disease. Ten healthy young male subjects performed IHE at 10% and 30% of maximum voluntary contraction (MVC) for 2-minutes (min) with or without arterial occlusion (AO), or 2-min of AO alone. Following each 2-min session, PI was determined during the 5-min recovery period. A significant difference in the recovery PI was observed between IHE, ischemic IHE, as well as AO alone. Exercise with AO significantly increased the reduction in the PI compared to exercise alone, or AO alone, at both 10% and 30%MVC. These results suggest, exercise-induced changes in the time course of the PI during recovery may potentially be a useful diagnostic tool. Exercise-induced ischemic state may potentially be a useful indicator for detecting arteriovascular disease, even if it is not detected by AO alone.     

Time course of changes in serum activity of the P3 isoform of pancreatic amylase isoenzyme in patients with acute pancreatitis

We studied the temporal sequence of serum P3 isoamylase changes in patients with acute pancreatitis, in comparison with serum pancreatic lipase (LPS) activity. Twenty-four hospitalized patients with acute pancreatitis, the onset not more than 12 h previously, were admitted to the study. Serum samples were collected daily for 6 days after onset for enzyme determinations. Measurements in the 48-h period after the onset of acute pancreatitis showed clinical sensitivities of total amylase, P3 isoform and LPS of 100%. During the following period, LPS and P3 isoform activities decreased with time with parallel changes, still showing diagnostic sensitivity significantly higher than total amylase. P3 isoform and LPS appear to be interchangeable markers of pathological release of pancreatic enzymes into the bloodstream during acute pancreatitis. However, LPS determination is more convenient because of its simplicity and shorter turnaround time.     

Skeletal muscle stiffness and pain following eccentric exercise of the elbow flexors

Stiffness and pain occurring after eccentric exercise have been studied in human elbow flexor muscles. Increased muscle stiffness and flexion deformities of the elbow developed immediately after the exercise and were greatest 1-4 days later. Muscle tenderness and pain experienced during elbow extension developed more slowly but were both maximal at the same time as the muscle stiffness. EMG recordings at times when there was pain and flexion deformity showed the biceps to be electrically silent. This demonstrates that the pain was not due to sustained electrical activity in the muscle and the flexion was a consequence of shortening of non-contractile elements, presumably the connective tissue. It is suggested that some response to damaged connective tissue may cause increased mechanical sensitivity of muscle receptors which, in turn, gives rise to pain when the muscle is stretched or pressed.