Stone P J, Calore J D, Snider G L, Franzblau C
Am Rev Respir Dis. 1979 Sep;120(3):577-87. doi: 10.1164/arrd.1979.120.3.577.
Hamsters were intratracheally instilled with saline solutions containing a high dose (145 to 220 micrograms) or a low dose (1.3 to 1.5 micrograms) of 3H-methylated pancreatic elastase or N-acetyl-(L-alanyl)3-L-alanine chloromethyl ketone-inactivated 3H-methylated pancreatic elastase. Only the lysyl residues of the elastase molecule were methylated and radiolabeled in a nonlabile manner. The 3H-methylated elastase preparation exhibited esterolytic and elastolytic activity, spectral properties, and emphysema-inducing properties indistinguishable from those of unmodified pancreatic elastase. There was no detectable hemorrhagic or emphysematous reaction with the inactivated 3H-methylated elastase, and this material was cleared from the lungs 11 times faster than the corresponding enzymatically active high dose of 3H-methylated elastase and 18 times faster than the corresponding enzymatically active low dose of 3H-methylated elastase. There were correspondingly higher amounts of radioactivity in the urine of hamsters treated with the inactivated elastase. All of the 3H radioactivity recovered from the urine was associated with epsilon-N-methyllysyl and epsilon-N,N-dimethyllysyl residues. Significant levels of radioactivity were found in the cells, primarily alveolar macrophages, lavaged from the lungs. The low dose of enzymatically active elastase caused neither detectable hemorrhage nor emphysema, both of which were associated with the high dose. At 144 days significant radioactivity (1,200 cpm) remained in the lungs of animals treated with high or low doses of enzymatically active elastase, whereas virtually no radioactivity (100 cpm) was found in the lungs of those treated with high or low doses of inactivated elastase. The data presented support the hypothesis that the formation of elastase complexes with alpha 1-protease inhibitor and alpha 2-macroglobulin is associated with the slower clearance and the retention of significant amounts of radioactivity in the lungs. Some of the residual radioactivity found in the hamster lungs might represent enzymatically active elastase complexed with alpha 2-macroglobulin and might offer an explanation for the progressive nature of emphysema induced by a single dose of elastase.
将含有高剂量（145至220微克）或低剂量（1.3至1.5微克）的3H-甲基化胰弹性蛋白酶或N-乙酰基-（L-丙氨酰基）3-L-丙氨酸氯甲基酮灭活的3H-甲基化胰弹性蛋白酶的盐溶液经气管内注入仓鼠体内。仅弹性蛋白酶分子的赖氨酰残基以稳定的方式被甲基化并进行放射性标记。3H-甲基化弹性蛋白酶制剂表现出的酯解和弹性解活性、光谱特性以及诱发肺气肿的特性与未修饰的胰弹性蛋白酶无异。用灭活的3H-甲基化弹性蛋白酶未检测到出血或肺气肿反应，并且该物质从肺中清除的速度比相应酶活性高剂量的3H-甲基化弹性蛋白酶快11倍，比相应酶活性低剂量的3H-甲基化弹性蛋白酶快18倍。相应地，用灭活弹性蛋白酶处理的仓鼠尿液中的放射性含量更高。从尿液中回收的所有3H放射性都与ε-N-甲基赖氨酰和ε-N，N-二甲基赖氨酰残基相关。在从肺中冲洗出的细胞（主要是肺泡巨噬细胞）中发现了显著水平的放射性。低剂量的酶活性弹性蛋白酶既未引起可检测到的出血也未引起肺气肿，而这两者都与高剂量相关。在144天时，用高剂量或低剂量酶活性弹性蛋白酶处理的动物肺中仍有显著放射性（1200 cpm），而用高剂量或低剂量灭活弹性蛋白酶处理的动物肺中几乎未发现放射性（100 cpm）。所呈现的数据支持这样的假设，即弹性蛋白酶与α1-蛋白酶抑制剂和α2-巨球蛋白形成复合物与清除较慢以及肺中大量放射性的保留有关。在仓鼠肺中发现的一些残留放射性可能代表与α2-巨球蛋白复合的酶活性弹性蛋白酶，并且可能为单剂量弹性蛋白酶诱发的肺气肿的进行性性质提供一种解释。
