Clowes G H, George B C, Villee C A, Saravis C A
N Engl J Med. 1983 Mar 10;308(10):545-52. doi: 10.1056/NEJM198303103081001.
Accelerated proteolysis of muscle is characteristic in patients with trauma or sepsis, but its cause is not well understood. Using rat muscle in vitro, we developed a bioassay to compare the proteolytic activity of plasma from 50 patients with trauma or sepsis with that of plasma from 14 normal volunteers and from 15 patients who had undergone "clean" elective surgical procedures. The mean proteolytic activity in the plasma of patients with trauma or sepsis was found to be 190 +/- 8.0 per cent of the control value (rat muscle incubated in medium alone), whereas the activity in normal plasma was 124 +/- 4.5 per cent (P less than 0.001). The activity in the plasma of patients who had undergone elective surgery was slightly elevated at 142 +/- 2.5 per cent (P less than 0.005). In 25 of the patients with trauma or sepsis the rate of amino acid release from one leg was measured by subtracting the concentration of tyrosine plus phenylalanine in the femoral artery plasma from that in the femoral vein; this rate correlated well with the bioactivity of the plasma in the bioassay system (r = 0.67, P less than 0.001). By means of ultrafiltration and chromatography, the plasma factor inducing proteolysis was isolated and found to be a peptide, probably containing sialic acid, with a chain of 33 amino acids and a molecular weight of approximately 4274 daltons.
创伤或脓毒症患者的肌肉蛋白水解加速是其特征，但病因尚不清楚。我们利用大鼠肌肉进行体外实验，开发了一种生物测定法，以比较50例创伤或脓毒症患者血浆与14名正常志愿者及15例接受“清洁”择期手术患者血浆的蛋白水解活性。结果发现，创伤或脓毒症患者血浆中的平均蛋白水解活性为对照值（仅在培养基中孵育的大鼠肌肉）的190±8.0%，而正常血浆中的活性为124±4.5%（P<0.001）。接受择期手术患者血浆中的活性略有升高，为142±2.5%（P<0.005）。在25例创伤或脓毒症患者中，通过用股静脉血浆中酪氨酸加苯丙氨酸的浓度减去股动脉血浆中的浓度来测量一条腿的氨基酸释放率；该速率与生物测定系统中血浆的生物活性密切相关（r=0.67，P<0.001）。通过超滤和色谱法，分离出诱导蛋白水解的血浆因子，发现其为一种肽，可能含有唾液酸，有33个氨基酸链，分子量约为4274道尔顿。
