共查询到20条相似文献，搜索用时 139 毫秒
1.
骨胳肌在乳酸生成和清除中的作用 总被引：1，自引：0，他引：1
孟思进 《武汉体育学院学报》2001,35(2):92-94
关于骨胳肌与乳酸代谢的研究已取得了很多重要进展。论述了不同强度运动时骨胳肌乳酸的生成及不同肌纤维清除乳酸的途径。以往认为骨胳肌无糖异生作用，但现在研究认为骨胳肌肌纤维具有糖异生作用。 相似文献
2.
通过对运动时线粒体是否缺氧和提高丙酮酸脱氢酶活性可降低肌乳酸的生成两方面,阐述运动时肌乳酸的产生机制。提出乳酸的生成可能是由于运动时丙酮酸的生成量大于线粒体的氧化磷酸能力,而不能简单认为是由于机体的缺氧造成的。 相似文献
3.
骨骼肌运动性疲劳乳酸机制研究进展 总被引：1，自引：0，他引：1
目前在生物化学、运动生理学的教科书中依然把乳酸作为代谢性酸中毒的原因，但许多科学家认为用乳酸中毒来解释代谢性酸中毒是没
有研究基础支持的。有实验表明，乳酸的产生并没有完全使肌肉收缩力量下降，酸性化缓和了因细胞外[K+]升高而导致的骨骼肌疲劳。乳酸可以
通过改变氯离子通道活性从而促进动作电位的产生，使骨骼肌在开始疲劳时仍可以保护兴奋的传播。乳酸通过膜屏障在细胞间和细胞内穿梭是
靠单羧酸转运蛋白推动的，它协同转运乳酸和氢离子。其中慢肌纤维中MCT1 含量最高，有利于摄取乳酸使进入细胞，而快肌中MCT4 含量较高，
有利于把乳酸送出。 相似文献
4.
5.
1细胞内乳酸穿梭学说的提出Brooks等人把离体的骨骼肌线粒体和心肌线粒体用培养基培养,发现乳酸转运蛋白MCT阻断剂CINN阻断了乳酸和丙酮酸在线粒体的氧化;乳酸脱氢酶LDH的阻断剂OX阻断了乳酸在线粒体中的氧化;不进行LDH的活性阻断时,乳酸在线粒体中的氧化率超过丙酮酸10-40%。暗示,线 相似文献
6.
肌纤维中介导乳酸转运的蛋白主要是单羧化物载体MCT1和MCT4，前者主要分布在氧化型纤维，后者主要分布在酵解型纤维。运动训练可提高两者在肌纤维中的表达，从而提高对乳酸的转运能力。载体蛋白MCT的表达及其机能的改变可能与运动性疲劳的产生有关。 相似文献
7.
非乳酸代谢的定量分析包括能力和功率两方面,非乳酸能能力的大小与运动时骨胳肌内磷酸原浓度的变化有关,而非乳酸能功率大小与磷酸原裂解速率有关。Fox曾提出一种简单实用的最大非乳酸能能力(AL Cmax)测试法,但未受到重视,其可靠性也未曾证明过。此外,最大非乳酸能功率(AL Pmax)测试的可靠性同样也没验证过。本研究旨在提供这两种测试的可靠性情况。 相似文献
8.
连续力竭性运动后大鼠血乳酸的持续升高 总被引：7，自引：0，他引：7
连续力竭性运动后,大鼠血乳酸和肌乳酸浓度显著升高,而肌糖原显著降低。虽经48小时休息,血和肌乳酸浓度以及肌糖原均未能恢复至安静水平,肌细胞内线粒体明显水肿,显示乳酸未被有效氧化或合成糖原。这可能与细胞膜的转运障碍及线粒体氧化还原酶系的机能障碍有关。 相似文献
9.
不同速度运动后大鼠骨骼肌氧化还原状态的变化及乳酸阈的形成 总被引：2，自引：0，他引：2
本研究的目的在于观察不同速度运动后大鼠骨骼肌氧化还原状态的变化及其与乳酸阈形成之间的关系。通过测定不同速度运动后 SD 大鼠骨骼机 NADH 和 NAD 含量变化发现,低强度运动后 NADH下降,中等强度运动后又升高,肌乳酸均有少量增加。在乳酸阈速度时,NADH 含量和 NADH/NAD 比值呈现出迅速增加的趋势。由此得出结论:中等强度运动后 NADH 含量升高主要是线粒体内 NADH 发生改变;肌肉 NADH/NAD 比值的变化对乳酸阈的形成是极其重要的调节因素。在中强度时细胞即开始向还原状态转变,可能对加速乳酸的积累和乳酸阈的形成具重要意义。 相似文献
10.
目的:研究递增负荷运动后肌氧和血乳酸的恢复特点及特征性指标的关联性,探索恢复评价的有效指标与科学化手段.方法:14名赛艇轻量级运动员进行递增负荷运动试验,采用静止休息的方式恢复至安静状态.用近红外光谱术(NIRS)监测运动时及恢复期主动肌氧含量的变化,提取肌氧恢复幅度(H)、半恢复时(TR),计算肌氧半恢复速率(RHbO2).在运动停止后即刻及恢复期测定血乳酸,找出峰值(Blamax)及峰值出现的时间(t)、恢复至30min时的血乳酸浓度(Bla30),计算乳酸清除速率(RBla).结果:肌氧含量与血乳酸的变化与氧化代谢水平和恢复程度相适应.肌氧半恢复速率RHbO2和血乳酸清除速率RBla存在显著的正相关(r=0.791,P＜0.01),回归方程存在显著意义.结论:肌氧和血乳酸的变化在内在机制上存在必然的联系,可以反映机体的恢复水平和氧化代谢能力.将RHbO2取代传统指标RBla应用于代谢能力和恢复评价具有可行性;NIRS为训练监控的科学化发展提供了有效的检测手段. 相似文献
11.
Federico Onali Carla M. Calò Myosotis Massidda Miguel M. Álvarez-Álvarez 《European Journal of Sport Science》2018,18(10):1376-1382
A common missense mutation (1470T > A) in gene SLC16A1 responsible for an amino acid substitution in protein MCT1 has been associated with differential lactate transport and hence, differences in physical performance and muscle injuries in relation to physical exercise. This study describes, for the first time, the worldwide variation of MCT1 variant 1470T > A at an intra- and inter-continental level. Two thousand five hundred and four individual genotypes of 26 populations clustered in 5 population groups have been analysed with data downloaded from the public database 1000 Genomes Phase 3 Browser. Several parameters of population differentiation and structure have been explored as well as selection signatures in the whole gene. Allele T, the common variant, shows extremely high values in Sub-Saharan African groups (frequencies 86–91%) as compared with the remaining world regions (69–49%). TT genotype also predominates in African groups, showing significant differences with the rest of world populations. In view of the evidence that the TT genotype is associated with clinical implications and a better predisposition to sprint/power performances, we suggest that the high presence of the TT genotype in African populations should be taken into account in future association studies at both medical and sports fields. 相似文献
12.
The aim of this study was to assess the responses of blood lactate and pyruvate during the lactate minimum speed test. Ten participants (5 males, 5 females; mean +/- s: age 27.1 +/- 6.7 years, VO 2max 52.0 +/- 7.9 ml kg -1 min -1 ) completed: (1) the lactate minimum speed test, which involved supramaximal sprint exercise to invoke a metabolic acidosis before the completion of an incremental treadmill test (this results in a ‘U-shaped’ blood lactate profile with the lactate minimum speed being defined as the minimum point on the curve); (2) a standard incremental exercise test without prior sprint exercise for determination of the lactate threshold; and (3) the sprint exercise followed by a passive recovery. The lactate minimum speed (12.0 +/- 1.4 km h -1 ) was significantly slower than running speed at the lactate threshold (12.4 +/- 1.7 km h -1 ) (P < 0.05), but there were no significant differences in VO 2 , heart rate or blood lactate concentration between the lactate minimum speed and running speed at the lactate threshold. During the standard incremental test, blood lactate and the lactate-topyruvate ratio increased above baseline values at the same time, with pyruvate increasing above baseline at a higher running speed. The rate of lactate, but not pyruvate, disappearance was increased during exercising recovery (early stages of the lactate minimum speed incremental test) compared with passive recovery. This caused the lactate-to-pyruvate ratio to fall during the early stages of the lactate minimum speed test, to reach a minimum point at a running speed that coincided with the lactate minimum speed and that was similar to the point at which the lactate-to-pyruvate ratio increased above baseline in the standard incremental test. Although these results suggest that the mechanism for blood lactate accumulation at the lactate minimum speed and the lactate threshold may be the same, disruption to normal submaximal exercise metabolism as a result of the preceding sprint exercise, including a three- to five-fold elevation of plasma pyruvate concentration, makes it difficult to interpret the blood lactate response to the lactate minimum speed test. Caution should be exercised in the use of this test for the assessment of endurance capacity. 相似文献
13.
The aim of this study was to assess the responses of blood lactate and pyruvate during the lactate minimum speed test. Ten participants (5 males, 5 females; mean +/- s: age 27.1+/-6.7 years, VO2max 52.0+/-7.9 ml x kg(-1) x min(-1)) completed: (1) the lactate minimum speed test, which involved supramaximal sprint exercise to invoke a metabolic acidosis before the completion of an incremental treadmill test (this results in a 'U-shaped' blood lactate profile with the lactate minimum speed being defined as the minimum point on the curve); (2) a standard incremental exercise test without prior sprint exercise for determination of the lactate threshold; and (3) the sprint exercise followed by a passive recovery. The lactate minimum speed (12.0+/-1.4 km x h(-1)) was significantly slower than running speed at the lactate threshold (12.4+/-1.7 km x h(-1)) (P < 0.05), but there were no significant differences in VO2, heart rate or blood lactate concentration between the lactate minimum speed and running speed at the lactate threshold. During the standard incremental test, blood lactate and the lactate-to-pyruvate ratio increased above baseline values at the same time, with pyruvate increasing above baseline at a higher running speed. The rate of lactate, but not pyruvate, disappearance was increased during exercising recovery (early stages of the lactate minimum speed incremental test) compared with passive recovery. This caused the lactate-to-pyruvate ratio to fall during the early stages of the lactate minimum speed test, to reach a minimum point at a running speed that coincided with the lactate minimum speed and that was similar to the point at which the lactate-to-pyruvate ratio increased above baseline in the standard incremental test. Although these results suggest that the mechanism for blood lactate accumulation at the lactate minimum speed and the lactate threshold may be the same, disruption to normal submaximal exercise metabolism as a result of the preceding sprint exercise, including a three- to five-fold elevation of plasma pyruvate concentration, makes it difficult to interpret the blood lactate response to the lactate minimum speed test. Caution should be exercised in the use of this test for the assessment of endurance capacity. 相似文献
14.
《European Journal of Sport Science》2013,13(6):367-374
Abstract The aim of this study was to determine whether an exogenous sodium lactate infusion increases blood lactate concentration and decreases performance during a 20-km time-trial. Highly trained male cyclists performed a 20-km time-trial with a saline (control) or sodium lactate infusion. Sodium lactate was infused at rates previously observed to raise blood lactate concentration by 2 mmol·l?1 in trained individuals cycling at 65% of maximum oxygen uptake. Blood lactate concentration increased (P≤0.0001) during both the control and sodium lactate trials compared with rest, with peak values of 9.6 and 10.6 mmol·l?1, respectively. The increase in sodium lactate over time was not significantly different from the control (P=0.34). Time to complete the time-trial and average power for the time-trial were not significantly different between the control (25.72±0.80 min; 348.0±32.4 W) and sodium lactate trials (25.58±0.93 min; 352.6±39.3 W). In addition, rating of perceived exertion, heart rate, and respiratory parameters did not differ between trials. In conclusion, when exogenous lactate is infused during a 20-km cycling time-trial, an exercise bout performed above the maximal lactate steady state, blood lactate concentration did not increase. Furthermore, exogenous lactate infusion did not decrease exercise performance, increase perceived exertion, or change respiratory parameters. Because lactate per se did not change performance outcomes or measured perceived exertion, we suggest that alternative objective measures of exercise intensity and performance be explored. 相似文献
15.
Tomás T. Freitas Julio Calleja-González Jorge Carlos-Vivas Elena Marín-Cascales 《Journal of sports sciences》2019,37(4):434-442
This study investigated the effects on neuromuscular performance of a 6-week Optimal Load Training (OLT) and a novel modified Complex Training (MCT) (complex pairs: the same exercise using a moderate and an OL) in basketball players, in-season. Eighteen male athletes were randomly assigned to one of the protocols. Anthropometric measurements were taken to evaluate body composition. Lower- and upper-body maximum dynamic strength, countermovement jump (CMJ), standing long jump (SLJ), 10-m sprint and change of direction (COD) were also assessed. Moderate-to-large strength gains (presented as percentage change ± 90% confidence limits) were obtained for half-squat (OLT: 10.8 ± 5.3%; MCT: 17.2 ± 11.6%) and hip thrust (OLT: 23.5 ± 17.7%; MCT: 28.2 ± 19.0%). OLT athletes achieved likely small improvements in sprint (1.6 ± 1.6%) and COD (3.0 ± 3.2%). Players in the MCT attained likely moderate improvements in COD (3.0 ± 2.0%) and possibly small in SLJ (2.5 ± 4.6%). No protocol relevantly affected CMJ or body composition. An ANCOVA test revealed unclear between-group differences. In conclusion, both protocols increased basketball players’ strength without the use of heavy loads (> 85% 1RM) and without impairing sprint, CMJ and SLJ performance. These findings suggest that basketball strength and conditioning professionals may use either method to counteract strength losses during the season. 相似文献
16.
Y Fukuba M L Walsh R H Morton B J Cameron C T Kenny E W Banister 《Journal of sports sciences》1999,17(3):239-248
The aim of this study was to measure serial changes in the rate of blood lactate clearance (gamma2) in response to sequential periods of training and detraining in four male triathletes aged 22-44 years. There were two major phases of training and taper, each lasting 4-5 weeks (training 1 = 5 weeks, taper 1 = 2 weeks, training 2 = 4 weeks and taper 2 = 2 weeks), in preparation for a triathlon competition. The training stimulus absorbed by each subject was carefully quantified from the duration and intensity of the training exercise. A serial weekly measure of each trainee's physical response to training was evaluated as the peak power, termed a 'criterion performance', developed by a subject during a 30 W x min(-1) ramp cycle ergometer test to exhaustion each week. During 30 min of recovery after this test, 13 samples of venous blood were drawn sequentially from a subject to measure the blood lactate recovery curve. The rate constant of blood lactate clearance was estimated by a non-linear least-squares regression technique. In addition, the concurrent time to peak lactate concentration and the peak lactate concentration were also estimated to help define changing lactate kinetics. The criterion performance generally declined throughout each period of incremental training and improved during each taper period, rising iteratively in this way to be clearly above baseline by the end of the second taper. The blood lactate clearance rate increased transiently in early training before declining from the middle of the first training period to the middle of the first taper; thereafter, gamma2 increased above baseline in each trainee throughout the remaining first taper and the major portion of the second training period, decreasing only in the final criterion performance test. The time to peak lactate declined from baseline throughout all phases of training and taper. Peak blood lactate increased in all subjects to the end of the first taper before declining by the end of the second training period, rising again to baseline levels during the second taper. The change in gamma2 was examined relative to the work rate achieved in cycle ergometry above an initial baseline score (deltaCP) and against concurrent peak blood lactate. There was a clear upward shift in gamma2 above baseline throughout the first and second training and taper in two subjects; this was less clear in the remaining two subjects, each of whom had a lower deltaCP. We conclude that this indicates improved lactate clearance, manifest by the change in gamma2 induced by endurance training. 相似文献
17.
18.
This study examined the influence of the regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and the endurance performance. Sixteen non-competitive, recreational female runners performed a discontinuous incremental treadmill test. The initial speed was set at 7 km · h?1, and increased every 3 min by 1 km · h?1 with a 30-s rest between the stages used for earlobe capillary blood sample collection. Lactate-speed data were fitted by an exponential-plus-constant and a third-order polynomial equation. The lactate threshold was determined for both regression equations, using all the coordinates, excluding the first and excluding the first and second initial points. Mean speed of a 10-km road race was the performance index (3.04 ± 0.22 m · s?1). The exponentially-derived lactate threshold had a higher correlation (0.98 ≤ r ≤ 0.99) and smaller standard error of estimate (SEE) (0.04 ≤ SEE ≤ 0.05 m · s?1) with performance than the polynomially-derived equivalent (0.83 ≤ r ≤ 0.89; 0.10 ≤ SEE ≤ 0.13 m · s?1). The exponential lactate threshold was greater than the polynomial equivalent (P < 0.05). The results suggest that the exponential lactate threshold is a valid performance index that is independent of the initial intensity of the incremental test and better than the polynomial equivalent. 相似文献
19.
Volianitis S Dawson EA Dalsgaard M Yoshiga C Clemmesen J Secher NH Olsen N Nielsen HB 《Journal of sports sciences》2012,30(2):149-153
Reduced hepatic lactate elimination initiates blood lactate accumulation during incremental exercise. In this study, we wished to determine whether renal lactate elimination contributes to the initiation of blood lactate accumulation. The renal arterial-to-venous (a-v) lactate difference was determined in nine men during sodium lactate infusion to enhance the evaluation (0.5 mol x L(-1) at 16 ± 1 mL x min(-1); mean ± s) both at rest and during cycling exercise (heart rate 139 ± 5 beats x min(-1)). The renal release of erythropoietin was used to detect kidney tissue ischaemia. At rest, the a-v O(2) (CaO(2)-CvO(2)) and lactate concentration differences were 0.8 ± 0.2 and 0.02 ± 0.02 mmol x L(-1), respectively. During exercise, arterial lactate and CaO(2)-CvO(2) increased to 7.1 ± 1.1 and 2.6 ± 0.8 mmol x L(-1), respectively (P < 0.05), indicating a -70% reduction of renal blood flow with no significant change in the renal venous erythropoietin concentration (0.8 ± 1.4 U x L(-1)). The a-v lactate concentration difference increased to 0.5 ± 0.8 mmol x L(-1), indicating similar lactate elimination as at rest. In conclusion, a -70% reduction in renal blood flow does not provoke critical renal ischaemia, and renal lactate elimination is maintained. Thus, kidney lactate elimination is unlikely to contribute to the initial blood lactate accumulation during progressive exercise. 相似文献