Extracellular hydrolases of the lung.
Extracellular hydrolases of the lung.
复制标题
肺的细胞外水解酶。
作者：
G. Hook
在肺泡和远端呼吸道的无细胞衬里材料中存在酸性水解酶。这些通过肺灌洗程序获得的胞外水解酶似乎是选定的种类，因为某些水解酶(β-N-乙酰氨基葡萄糖苷酶和α-甘露糖苷酶)活性很高，而其他水解酶(β-葡萄糖醛酸酶和芳基硫酸酯酶)几乎检测不到。对这些水解酶的来源进行了探讨。无论是血清渗漏还是细胞损伤都不能解释灌洗液中细胞外水解酶的存在。丙烯酰胺凝胶上的凝胶迁移率表明，细胞外的水解酶通常不同于血清中的水解酶。用乳酸脱氢酶等胞质可溶性酶来监测细胞损伤，表明胞外水解酶不是由灌洗过程中的细胞渗漏引起的。水解酶与细胞外发现的水解酶类似，与从肺组织匀浆中分离出的高度纯化的无溶酶体的板层小体有关。细胞外水解酶可能是肺泡上皮2型细胞在选择板层小体的过程中所选择的。
A pool of acid hydrolases exists within the acellular lining material of the alveoli and distal airways of the lungs. These extracellular hydrolases, obtained using pulmonary lavage procedures, appear to be of a selected variety insofar as some hydrolases (beta-N-acetylglucosaminidase and alpha-mannosidase) are highly active while others (beta-glucuronidase and arylsulfatase) are barely detectable. The origins of these hydrolases were investigated. Neither leakage of serum nor cell damage can account for the presence of the extracellular hydrolases in lavage effluents. Electrophoretic mobilities on acrylamide gels indicate that the extracellular hydrolases generally differ from those found in serum. Cytoplasmic soluble enzymes such as lactate dehydrogenase were used to monitor cell damage and show that the extracellular hydrolases did not originate from cell leakage during the lavage procedure. Hydrolases similar to those found extracellularly are associated with highly purified lysosome-free lamellar bodies isolated from homogenates of lung. The extracellular hydrolases are probably selected by the type 2 cells of the pulmonary alveolar epithelium during their selection of lamellar bodies.