Bowers W E
J Exp Med. 1972 Dec 1;136(6):1394-403. doi: 10.1084/jem.136.6.1394.
10 acid hydrolases known to be lysosomal in other tissues were detected in rat thoracic duct lymphocytes (TDL). Except for cathepsin D, all these enzymes occurred in lower levels in TDL than in rat spleen. Fractionation by means of differential centrifugation revealed two types of distribution patterns. Most of the total cathepsin D activity appeared in a high-speed supernatant (S), whereas the other acid hydrolases associated mainly with a high-speed pellet (P). Further studies by isopycnic centrifugation in a sucrose density gradient showed that all the enzymes, including a small portion of cathepsin D, sedimented around a modal density of 1.18. In contrast, most cathepsin D activity was recovered in a soluble, unsedimentable form. These results suggest the presence of two populations of lysosomes. Because the possibility could be excluded that other cell types contaminated the lymphocyte preparations, it is concluded that both lysosomal populations arise from TDL.
在大鼠胸导管淋巴细胞（TDL）中检测到10种已知在其他组织中存在于溶酶体的酸性水解酶。除组织蛋白酶D外，所有这些酶在TDL中的含量均低于大鼠脾脏。通过差速离心进行分级分离揭示了两种分布模式。组织蛋白酶D的总活性大部分出现在高速上清液（S）中，而其他酸性水解酶主要与高速沉淀（P）相关。在蔗糖密度梯度中进行等密度离心的进一步研究表明，包括一小部分组织蛋白酶D在内的所有酶都在1.18的模态密度附近沉降。相比之下，大部分组织蛋白酶D活性以可溶、不可沉降的形式回收。这些结果表明存在两种溶酶体群体。由于可以排除其他细胞类型污染淋巴细胞制剂的可能性，因此得出结论，两种溶酶体群体均来自TDL。
