Grøgaard B, Parks D A, Granger D N, McCord J M, Forsberg J O
Am J Physiol. 1982 May;242(5):G448-54. doi: 10.1152/ajpgi.1982.242.5.G448.
Mucosal albumin clearance was measured in jejunal segments of dogs under control conditions, after arterial occlusions of varying duration (15 min-4 h), and during intraluminal perfusion with hypoxanthine-xanthine oxidase. Albumin clearance rates were estimated from the luminal perfusion rate and the activity of protein-bound 125I in the perfusate and plasma. Arterial occlusion of 30-min to 4-h duration produced a significant increase in mucosal albumin clearance. The magnitude of the rise in albumin clearance was directly related to the duration of arterial occlusion. Pretreatment with superoxide dismutase, a superoxide radical scavenger, or allopurinol, a xanthine oxidase inhibitor, did not prevent the increased albumin clearance induced by 1 h of occlusion. Intraluminal perfusion with hypoxanthine-xanthine oxidase significantly increased mucosal albumin clearances. This increase was prevented by superoxide dismutase. The results of this study indicate that arterial occlusions and enzymatically generated superoxide radicals increase mucosal albumin clearance.
在对照条件下、不同时长（15分钟至4小时）的动脉闭塞后以及腔内灌注次黄嘌呤-黄嘌呤氧化酶期间，测定犬空肠段的黏膜白蛋白清除率。根据管腔灌注速率以及灌注液和血浆中与蛋白质结合的125I的活性来估算白蛋白清除率。持续30分钟至4小时的动脉闭塞导致黏膜白蛋白清除率显著增加。白蛋白清除率升高的幅度与动脉闭塞的时长直接相关。用超氧化物歧化酶（一种超氧阴离子清除剂）或别嘌呤醇（一种黄嘌呤氧化酶抑制剂）进行预处理，不能阻止1小时闭塞所诱导的白蛋白清除率增加。腔内灌注次黄嘌呤-黄嘌呤氧化酶显著增加黏膜白蛋白清除率。超氧化物歧化酶可阻止这种增加。本研究结果表明，动脉闭塞和酶促产生的超氧自由基会增加黏膜白蛋白清除率。
