Lysosomal enzyme release from normal human polymorphonuclear leukocytes in response to particulate stimuli

Abstract

The microbicidal capacity of polymorphonuclear (PMN) leukocytes of normal human subjects was evaluated by estimating the release of lysosomal enzymes from normal cells and cells rendered incapable of ingesting particles by treatment with cytochalasin B, on exposure to a particulate stimulus-serum treated zymosan (STZ). The release of lysosomal enzymes namely beta-glucuronidase, lysozyme, acid phosphatase, alkaline phosphatase was found to be 16.28%, 27.84%, 20.54%, 15.40% respectively. The cells rendered incapable of ingesting particles showed enhanced response. The percentage release of beta-glucuronidase, lysozyme, acid and alkaline phosphatase was increased to 20.58%, 37.95%, 25.87% and 33.04% respectively. This type of response in cytochalasin B treated PMN leukocytes is due to the conversion of these cells into “secretory cells”, which release lysosomal enzymes outside the cell, by the process of reverse endocytosis.