Inhibition by a capsaicin antagonist (capsazepine) of capsaicin-induced swimming capacity increase in mice

We investigated the endurance swimming capacity of mice injected with CAP antagonist (capsazepine). The increase of endurance swimming capacity by the administration of CAP was significantly suppressed by the injection of capsazepine. At the same time, serum adrenaline secretion, which was induced by CAP, was depressed by capsazepine. These findings suggested that the increase in endurance swimming capacity by CAP was mediated by the CAP receptor.     

Biological Effects of Flammulina Velutipes Richin RE on Chinese Kunming Mice

ＢｉｏｌｏｇｉｃａｌＥｆｆｅｃｔｓｏｆＦｌａｍｍｕｌｉｎａＶｅｌｕｔｉｐｅｓＲｉｃｈｉｎＲＥｏｎＣｈｉｎｅｓｅＫｕｎｍｉｎｇＭｉｃｅＬｉａｎｇＤｉｎｇｂａｎｇ（梁定邦）；ＣｕｉＤｅｆａｎｇ（崔德芳）；ＺｈａｎｇＪｉｎｔｏｎｇ（张金桐）（Ｄｅｐａｒｔｍ...     

Effect of swimming training on antioxidant enzymes in kidney of young and old mice

The current study was undertaken to investigate the effect of swimming training on the antioxidant enzyme system in kidney of young and old mice. Both young and old mice, aged 2 and 26 months old, respectively, were divided into the sedentary and swimming-trained groups. The trained mice underwent a 6-week swimming program (1 h/day, 5 days/week) in water at 35-36 degrees C. Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity was significantly decreased with aging but was not influenced by swimming training, such changes being similar to those noted for catalase activity rather than for glutathione peroxidase activity. After swimming training Mn-SOD activity increased significantly only in old mice but was unaffected by aging. Although neither aging nor swimming training had overt effect on the expression of Cu,Zn-SOD mRNA, the immunoreactive Cu,Zn-SOD content in young mice decreased significantly after the training. Meanwhile, Mn-SOD mRNA expression in old mice was reduced by half after swimming training, accompanied by a significant decrease in its immunoreactive content; unexpectedly, however, Mn-SOD content in young mice did not parallel its mRNA expression. These findings suggest that the antioxidant enzyme system in mouse kidney trends to be down-regulated with aging, and that swimming training fails to attenuate such reduced levels of the antioxidant enzymes.     

Abnormalities in plasma and red blood cell fatty acid profiles of patients with colorectal cancer

Intravenous injection of stearoyl vanillylamide (C18-VA), a nonpungent capsaicin (CAP) analog, enhances adrenaline secretion significantly and as effectively as CAP in rats. Because swimming capacity was enhanced by CAP in mice due to CAP-induced adrenal catecholamine secretion, we investigated the effects of oral administration of C18-VA on swimming capacity using an adjustable-current water pool. Male Std ddY 6-wk-old mice were fed a commercial diet for this study and one group was orally administered C18-VA via a stomach tube. Treated mice were able to swim longer before exhaustion than the control mice (62.9 +/- 5.6 vs. 49.6 +/- 7. 0 min, P < 0.05). The swimming capacity of two groups administered C18-VA (0.02 and 0.033 mmol/kg) was significantly greater than that of those administered vehicle alone, (P < 0.05). Substance P concentration in cerebrospinal fluid, which is involved in pain transmission and is the first direct measure of pungency, was not affected by C18-VA administration. In an experiment examining the effects of C18-VA on serum adrenaline concentration, adrenaline was significantly greater in C18-VA treated mice than in controls at 2-h post-dose (C18-VA group, 26.09 +/- 2.82; control group 13.29 +/- 0. 96 microg/L, P < 0.01). In a separate study free fatty acids in serum were elevated in treated mice at 2-h post-dose (P < 0.01). While serum glucose concentration was not affected. These results suggest that C18-VA increased swimming capacity of mice via adrenaline release, independent of pungency. In addition, the present study suggests the usefulness of its application to humans.     

Skeletal muscle fatigue and physical endurance of young and old mice

In order to evaluate the role played by muscular and extramuscular factors in the development of fatigue in old age, the time course of fatigue in isolated skeletal muscles and spontaneous motor activity and endurance of whole animals were monitored using young (3-6 months) and old (34-36 months) CF57BL/6J mice. The isolated extensor digitorum longus (EDL) and soleus muscles from old mice had smaller (P < 0.05) mass and developed lower (P < 0.02) maximal tetanic tension at 100-Hz stimulation than the muscles of young mice. During stimulation at 30 Hz every 2.5 s, a 50% decline in original tetanic tension occurred by 109 s in young EDL and 129 s in old EDL, but by 482 s in young soleus and 1134 s (projected) in old soleus, indicating more (P < 0.05) resistance to fatigue in old than young soleus. However, the old mice showed significantly fewer (P < 0.002) spontaneous ambulatory movements than the young mice. On a treadmill with a belt speed of 10 m/min at an inclination of 0 degrees, the old mice could only run for 22 min compared to 39 min ran by young mice (P < 0.02). They took more rest periods (P< 0.02) than the young mice. In a quantitative swimming monitor, the old mice swam for a shorter (P < 0.05) time than young mice (20.4 min compared to 28.6 min). Integrated swimming activity at 20 min was smaller (P < 0.05) in old mice than in young mice (413 g/s compared to 628 g/s). Hence increased fatigue in old age is not caused by impairment of processes within the muscles, but by impairment of central or extramuscular processes.     

Increase of heart rate and determination of W170 as a measure of physical working capacity in children 5 to 14 years of age (author's transl)

1. Exercise testing with stepwise increasing workload was performed in 257 healthy children (134 boys, 123 girls) on a bicycle ergometer, which was independent of variations in pedal speed within a certain range. The procedure of exercise was adapted to the children as far as possible. 2. Nomograms and standard values for heart rate during exercise and for physical working capacity at a heart rate of 170/min (W170) were established. The increase of heart rate (from 1.0 to 2.5 Watt/kg) was well correlated to the age, length, body weight and body surface. If heart rate, respectively W170 are related to workload per kg body weight, results are dependent on sex, but not on age. 3. By means of the new standard values a rough evaluation of cardiorespiratory condition is possible, if the heart rate is measured at moderate exercise during steady state. A more precise assessment of the cardio-respiratory fitness is granted by the W170. By this method physical working capacity can be determined in children with heart diseases in a relative simple manner. 4. Normally in stepwise increasing loads the exercise takes 6 minutes per workload. If this time is reduced, an underestimation of the expected heart rate, respectively an overestimation of W170 is observed, which depends on the extent of the shortening of exercise.     

The Morris water-escape task in mice: strain differences and effects of intra-maze contrast and brightness

The Morris water-escape task is an extensively used experimental paradigm to assess the spatial discrimination performance and effects of brain lesions and drugs on this performance. In the first experiment, we compared the acquisition of this task by different strains (CFW1, BALB, NMRI, and C57BL) of mice and their performance in a probe trial. In a second experiment, C57BL mice were tested in Morris mazes where black and white tanks were combined with white or black platforms to investigate if and how the contrast between the tank and the platform affects the performance of the mice. In addition, four brightness conditions were compared to investigate whether or not the degree of brightness of the tank itself affects the learning performance. The results of these experiments indicated that 1. mice could readily learn the Morris task, 2. one of the contrast conditions affected the swimming speed, 3. the maze brightness per se did not affect water escape performance at all, and that 4. the swimming speed can strongly bias the outcome of Morris water-escape experiments in mice.     

三流非对称中间包流场水模拟研究

在保证产量的情况下,为使夹杂物充分上浮去除,钢水温度均匀,进一步提高某钢厂320 mm×480 mm连铸方坯的生产质量,针对三流非对称中间包,设计1∶3水模拟试验和数值模拟,进行不同拉速和有无挡坝的研究。通过速度场和温度场的数值模拟以及不同拉速下的水模拟,可以发现,随着拉速的增加,三个水口的停留时间减小,并且三个水口的停留时间有一定差距。添加挡坝后随着拉速的增加,平均停留时间减小得更为缓慢。速度场和温度场的分布规律并不随拉速的变化而变化,但拉速的增加会使中间包内的速度和温度上升。     

Behavioral assessment of neuroleptics (3)--Schizophrenia negative symptoms-like model induced by PCP

Immobility induced by forced swimming is well known as an animal model of depression. To develop an animal model for the negative symptoms of schizophrenia, in particular, the depressive symptoms, the effect of phencyclidine (PCP) on immobility in the forced swimming test was investigated in mice, since PCP produces negative symptoms-like behavioral changes in humans. Repeated treatment with PCP (10 mg/kg/day, sc, once a day for 14 days) prolonged the immobility time in the forced swimming test 24 hr after the final injection compared with saline treatment; the effect was not obtained by single treatment with PCP (10 mg/kg), or by repeated treatment with methamphetamine (0.3 and 1 mg/kg/day, sc, once a day for 14 days). The enhancing effect of PCP on the immobility persisted for at least 21 days after the withdrawal of the drug. Desipramine (10 mg/kg, po) attenuated the immobility induced by the forced swimming in mice repeatedly treated with saline. The enhancing effect of PCP on the immobility was attenuated by risperidone (0.3 mg/kg), clozapine (3 and 10 mg/kg), and desipramine (20 and 50 mg/kg), whereas haloperidol (0.3 and 1 mg/kg) had no effect. These results suggest that the enhancement of immobility in the forced swimming test brought about by repeated PCP treatment could be used as a model of the negative symptoms, particularly the depression, of schizophrenia.     

Is tube-escape learning by protozoa associative learning?

The ciliate protozoa, Stentor and Paramecium, have been reported to escape from the bottom end of narrow capillary tubes into a larger volume of medium with increasing rapidity over the course of trials. This change in behavior has been considered an apparent example of associative learning. This decrease in escape time is not due to a change in the protozoa's environment, their swimming speed, frequency of ciliary reversals, or the proportion of time spent forward or backward swimming. Instead, most of the decrease results from a decrease in the proportion of time spent in upward swimming. However, a similar decrease in upward swimming occurs when the task is altered to require escape from the upper end of the capillary tubes. Because the protozoa exhibit the same change in behavior regardless of the locus of the reinforcing stimulus, tube-escape learning is not associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Glutathone and glutathione ethyl ester supplementation of mice alter glutathione homeostasis during exercise

The present study examined the effect of glutathione (GSH) and glutathione ethyl ester (GSH-E) supplementation on GSH homeostasis and exercise-induced oxidative stress. Male Swiss-Webster mice were randomly divided into 4 groups: starved for 24 h and injected with GSH or GSH-E (6 mmol/kg body wt, i.p.) 1 h before exercise, starved for 24 h and injected with saline (S); and having free access to food and injected with saline (C). Half of each group of mice was killed either after an acute bout of exhaustive swimming (E) or after rest (R). Plasma GSH concentration was 100-160% (P < 0.05) higher in GSH mice vs. C or S mice at rest, whereas GSH-E injection had no effect. Plasma GSH was not affected by exercise in C or S mice, but was 44 and 34% lower (P < 0.05) in E vs. R mice with GSH or GSH-E injection, respectively. S, GSH- and GSH-E-treated mice had significantly lower liver GSH concentration and the GSH:glutathione disulfide (GSSG) ratio than C mice. Hepatic and renal GSH and the GSH:GSSG ratio were significantly lower in E vs. R mice in all groups. GSH-E-treated mice had a significantly smaller exercise-induced decrease in GSH vs. C, S, and GSH-treated mice and no difference in the GSH:GSSG ratio in the kidney. Activities of gamma-glutamylcysteine synthetase and gamma-glutamyltranspeptidase in the liver and kidney were not affected by either GSH treatment or exercise. GSH concentration and the GSH:GSSG ratio in quadriceps muscle were not different among C, S and GSH-treated mice, but significantly lower in GSH-E-treated mice (P < 0.05). Hepatic malondialdehyde (MDA) content was greater in exercised mice in all but GSH-E-treated groups. GSH and GSH-E increased MDA levels in the kidney of E vs. R mice, but attenuated exercise-induced lipid peroxidation in muscle. Swim endurance time was approximately 2 h longer in GSH (351 +/- 22 min) and GSH-E (348 +/- 27) than S mice (237 +/- 17). We conclude that 1) acute GSH and GSH-E supplementation at the given doses does not increase tissue GSH content or redox status; 2) both GSH and GSH-E improve endurance performance and prevent muscle lipid peroxidation during prolonged exercise; and 3) while both compounds may impose a metabolic and oxidative stress to the kidney, this side effect is smaller with GSH-E supplementation.     

Effects of pimozide on escape and discrimination performance in a water-escape task.

Three experiments studied the effects of pimozide (0.2 and 0.4 mg/kg) on discrimination learning of 255 male CD1 mice in a water-escape paradigm in which the degree of motor difficulty was manipulated by varying water temperature. The drug marginally affected escape latencies in relatively warm water (25°C) but markedly disrupted escape latencies when the task was more demanding (e.g., 15 and 20°C water). The escape deficits, however, were not accompanied by disturbances in the acquisition of position discrimination or cue discrimination responses when Ss were required to make the highly prepared response of swimming to light or the contraprepared response of swimming to dark. Data suggest that in tasks involving aversive motivation, pimozide influences performance through its effects on response maintenance but does not appear to affect either associative or motivational processes. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lung and heart impairment in patients with chronic cor pulmonale associated or not with acute myocardial infarction. Anatomoclinical and morphometric study

Pinoline (6-methoxy-1,2,3,4-tetrahydro-beta-carboline) is a naturally occurring compound in the mammalian body which inhibits serotonin (5-hydroxytryptamine) uptake and monoamine oxidase-A activity. The present study was designed to assess potential antidepressant- or anxiolytic-like behavioural effects of pinoline in rat forced swimming, open field and elevated plus-maze tests. In the forced swimming test pinoline dose-dependently reduced the immobility time, starting from a dose of 8 mg kg-1. In the open field test pinoline reduced the total open field activity. This effect was significant at 20 mg kg-1, whereas the dose of 15 mg kg-1 only significantly reduced the number of rearings. In the plus-maze test pinoline decreased the total number of arm entries, the number of line crossings and time spent in the open part of the apparatus, but increased the number of approaches to the open part of the maze. The effects of pinoline were dose-dependent in all three behavioural tests used. Since antidepressant drugs reduce the immobility time in the forced swimming test but typically inhibit activity in open field and elevated plus-maze tests, the behavioural effects of pinoline resemble those of drugs with an antidepressant profile.     

Effect of endurance exercise training on muscle glycogen supercompensation in rats

The purpose of this study was to test the hypothesis that the rate and extent of glycogen supercompensation in skeletal muscle are increased by endurance exercise training. Rats were trained by using a 5-wk-long swimming program in which the duration of swimming was gradually increased to 6 h/day over 3 wk and then maintained at 6 h/day for an additional 2 wk. Glycogen repletion was measured in trained and untrained rats after a glycogen-depleting bout of exercise. The rats were given a rodent chow diet plus 5% sucrose in their drinking water and libitum during the recovery period. There were remarkable differences in both the rates of glycogen accumulation and the glycogen concentrations attained in the two groups. The concentration of glycogen in epitrochlearis muscle averaged 13.1 +/- 0.9 mg/g wet wt in the untrained group and 31.7 +/- 2.7 mg/g in the trained group (P < 0.001) 24 h after the exercise. This difference could not be explained by a training effect on glycogen synthase. The training induced approximately 50% increases in muscle GLUT-4 glucose transporter protein and in hexokinase activity in epitrochlearis muscles. We conclude that endurance exercise training results in increases in both the rate and magnitude of muscle glycogen supercompensation in rats.     

The validity of swimming training for two-year-old thoroughbreds

To investigate the validity of swimming training, the following matters were considered: 1) changes in the performance capacity, 2) changes in the constitution and 3) frequency of locomotor diseases. These were evaluated during a training program including both conventional exercise on a track and swimming. In this study, 24 two-year-old thoroughbred horses were studied, and divided into the following three groups: Group A, trained by only running; Group B, trained by running plus a gradual increase in swimming; Group C, trained by running plus constant swimming. As a result of standardized exercise tests, only the intercepts of the 3 regression curves between the speed and the blood lactate concentration in Group B increased significantly as the training progressed. While the growth in height in Groups B and C were greater than in Group A, the increase in girth and weight in Groups B and C were smaller than in Group A. The percentages with locomotor diseases during this experiment in Groups A, B, and C were 62.5%, 12.5% and 25.0%, respectively, and there was a significant difference (p < 0.05) between Group A and Group B. As mentioned, it was suggested that a training program including swimming training is seen as being useful for improvement in performance capacity, since it can reduce locomotor diseases in young horses and allow for smooth progress in future training.     

The effect of bromantane on the physical work capacity of laboratory animals

The positive effect of bromantan (0.5-50 mg/kg) on the efficiency of physical work of mice and rats (swimming test, running on a treadmill) exceeds that of phenamine administered in optimal doses by 1.3-1.6 times. Such an effect of bromantan lasts no less than 24 h. The drug delays decrease of physical efficiency and restores it sooner in repeated extreme running loads, prevents in rats the corresponding electron-microscopic changes in the cardiomyocyte and myocyte mitochondria of the skeletal muscles. The data obtained suggest that the positive effect of bromantan on the physical efficiency is associated not only with its psychostimulating action but also with the membrane-protecting effect.     

Increased flexibility and selectivity in spatial learning of transgenic mice ectopically expressing the neural cell adhesion molecule L1 in astrocytes

The expression of the neural cell adhesion molecule L1 is altered by neuronal activity and promotes neurite outgrowth in vitro. To study the effects of L1 on learning and synaptic plasticity, transgenic mice have been created which express L1 ectopically in glial fibrillary acidic protein (GFAP) expressing astrocytes. Ninety mice, including GFAP-L1-transgenic mice from two genetic backgrounds and their littermates, were tested for swimming navigation learning in the Morris water maze according to a standardized protocol. While learning the position of an invisible target platform and also relearning its position after relocation, GFAP-L1-transgenic mice spent a greater fraction of their swim time in the target quadrant. Moreover, they showed a more rapid improvement of escape performance during the first day of training. Factor analysis revealed that this difference in swimming pattern could not be explained by non-cognitive factors. Factor analysis also revealed that, during a probe trial, the GFAP-L1-transgenic mice spent comparatively less time in the old target quadrant than predicted by the increased searching they had shown during acquisition learning. Hence, ectopic expression of L1 by astrocytes in mice appears to be linked to a factor which increases behavioural flexibility and selectivity while learning and relearning, but concomitantly may lead to a relative reduction of spatial retention.     

连续铸钢过程中结晶器的传热研究

 为了研究结晶器内壁温度的分布,设计了模拟结晶器工作过程的实验装置,并进行了实验。实验结果表明,结晶器内壁温度趋近于冷却水温度。基于实验,推导了结晶器边界等效导热系数。该系数用于解决金属和冷却水之间的传热,即反映结晶器的传热能力。用等效导热系数处理结晶器的边界传热,对包括结晶器在内的连铸凝固进程温度场进行数值模拟既简单又方便,并且计算结果与实验结果符合。还讨论了拉坯速度和冷却水流量对结晶器温度场的影响。     

Epidemiology of free-living amoebae in the waters of Strasbourg (France) (author's transl)

164 strains of free-living amoebae were isolated from public drinking water supplies, swimming pools and official swimming ponds in Strasbourg; 11 genera and 16 species were identified. Some strains of Acanthamoeba are pathogenic for mice by intracerebral inoculation. Among the two strains of Naegleria found none is pathogenic. The results concerning free-living amoebae are compared with the level of chlorine and bromine and with the presence of bacteria in swimming pools.     

全尾砂浓密特性研究及其在浓密机设计中的应用

在实验装置中添加了转子导流系统,使模型装置更接近于现场高效浓密机.采用均匀设计方法,以单位面积固体处理量和底流体积分数作为尾砂浓密效果的评价指标,考察各因素对尾砂浓密效果的影响.结果表明:单位面积固体处理量与絮凝剂单耗正相关,最佳入料体积分数为6.56%;底流体积分数与入料体积分数、停留时间和絮凝剂单耗均正相关.最后通过凯奇沉降模型对沉降曲线进行分析,速度限制层一般为过渡区与压缩区的交界处,根据实验结果和尾砂日处理量计算得出浓密机的最小直径为14m.