Hermiston R T, Bonde-Petersen F
Eur J Appl Physiol Occup Physiol. 1975 Dec 5;34(4):291-302. doi: 10.1007/BF00999942.
Isometric and isotonic endurance levels of both elbow flexors and knee extensors were tested during inspired gas mixtures of ca. 10%, 21% or 100% oxygen in nitrogen. The four work loads were set a 25, 50, 60 and 70% of maximal volitional isometric strength (IS). The isotonic exercise routine was carried out using weight lifting techniques of 20 repetitions per min from 75 degrees to 105 degrees of elbow flexion and knee extensions respectively. Prior to, during, and after the endurance experiments 133Xe clearance was monitored by light weight scintillation counters. A depot of 0.1 to 0.2 ml of isotonic saline containing 50 to 150 muCi of the isotope was used as an intramuscular tracer. The exercise clearance values varied inversely to the test load during isometric exercise. Isotonic exercise for both elbow flexors and knee extensors showed increasing clearance values up to 60% IS. Above this level a decrease in total clearance was recorded. Oxygen tension had no statistical effect on the clearance values. However, the relatively large scatter of the 133Xe clearance method, and an inhomogenous perfusion of skeletal muscle may have masked any anticipated effect of the various O2 tensions. Variations due to the raised intramuscular pressure appeared to be much more dominant than the hypothezised variation due to the 3 set oxygen tensions.
在氮气中分别含有约10%、21%或100%氧气的吸入气体混合物期间，测试了肘屈肌和膝伸肌的等长和等张耐力水平。四个工作负荷设定为最大随意等长力量（IS）的25%、50%、60%和70%。等张运动程序采用举重技术进行，每分钟分别进行20次重复，肘部从75度屈曲到105度，膝部进行伸展。在耐力实验之前、期间和之后，用轻型闪烁计数器监测133Xe清除率。将含有50至150微居里同位素的0.1至0.2毫升等渗盐水作为肌肉内示踪剂。在等长运动期间，运动清除率值与测试负荷成反比。肘屈肌和膝伸肌的等张运动在达到60%IS之前清除率值不断增加。高于此水平，总清除率下降。氧张力对清除率值没有统计学影响。然而，133Xe清除方法相对较大的离散度以及骨骼肌灌注不均匀可能掩盖了各种氧张力的任何预期影响。由于肌肉内压力升高引起的变化似乎比假设的由3种设定氧张力引起的变化更为显著。
