The effect of SH-groups of cysteine on the rate of oxygen uptake by some homogenates of the rabbit tissues

Abstract

The effect of SH-groups of cysteine on the rate of oxygen uptake by some homogenates of the rabbit tissues. Acta Physiol. Pol., 1977, 28 (6): 541-551. In the present experiments the effect of SH-groups of cysteine on the respiration rate of homogenates of kidney, liver, brain, myocardium and skeletal muscle was investigated in the rabbit. Using the Warburg's method of respirometry it was found that cysteine added to the incubation medium modifies oxygen uptake by the above-mentioned tissue homogenates and that this reaction depends both on the kind of tissue and cysteine concentration in the medium. Addition of cysteine to the incubation medium in the concentration of 0.1 mg/ml exerted only slight, insignificant influence on the tissue respiration but in the concentration of 0.4 mg/ml it increased the respiration rate in homogenates of kidney (by 30%), liver (by 55%) and skeletal muscle (by 59%). Cysteine added in the concentration of 0.8 mg/ml increased the respiration rate of all the examined tissue homogenates. The strongest effect of cysteine in this concentration was found in the liver and skeletal muscle homogenates (an increase in O2 uptake by 88% and 89% respectively) and the lowest in the myocardium (by 53%). Under control conditions (without cysteine) kidney homogenates had the highest oxygen consumption and skeletal muscle ones the lowest.