Lei G H, Zhang W, Wu J C, Piao Y J, Bao Y Y, Huang H
Central Laboratory, Department of Pediatrics of Nanfang Hospital, First Military Medical University, Guangzhou 510515.
Shi Yan Sheng Wu Xue Bao. 1998 Mar;31(1):7-11.
The effects of Con A, WGA, Zymosan A on macrophage cytosolic pH and outflow of lysosomal content through exocytosis were studied with SNAFL-calcein and FITC-Dextran on ACAS570. The results showed all three ligands could induce macrophage cytosolic acidification in about 10 min and kept at the same level hereafter; outflow of lysosomal fluorescent probe through exocytosis appeared in 15-20 min. In resting conditions, macrophage lysosomes mainly distributed in cell center; after stimulated for 15 min by three ligands, the number of lysosomes increased in membrane periphery, in 25-30 min lysosomes moved back toward cell center. We proposed that ligands induced lysosomal pH rises was a basic factor for outflow of lysosomal content through exocytosis, cytosolic acidification inhibited receptor-mediated endocytosis. Cytosolic acidification and outflow of lysosomal content through exocytosis were the results of cellular self-regulation and self-protection during receptor-mediated endocytosis.
利用SNAFL-钙黄绿素和异硫氰酸荧光素标记的葡聚糖，在ACAS570上研究了刀豆蛋白A、小麦胚凝集素、酵母聚糖A对巨噬细胞胞质pH值以及溶酶体内容物通过胞吐作用流出的影响。结果显示，所有这三种配体均可在约10分钟内诱导巨噬细胞胞质酸化，并在此后维持在同一水平；溶酶体荧光探针通过胞吐作用流出出现在15 - 20分钟。在静息状态下，巨噬细胞溶酶体主要分布在细胞中心；在三种配体刺激15分钟后，溶酶体数量在膜周边增加，在25 - 30分钟时溶酶体又向细胞中心移动。我们提出，配体诱导的溶酶体pH值升高是溶酶体内容物通过胞吐作用流出的一个基本因素，胞质酸化抑制受体介导的内吞作用。胞质酸化和溶酶体内容物通过胞吐作用流出是受体介导的内吞过程中细胞自我调节和自我保护的结果。
