Hyposmolarity stimulates myeloperoxidase exocytosis from human polymorphonuclear leukocytes.
Medium hyposmolarity induced in human polymorphonuclear leukocytes treated with cytochalasin B a rapid exocytosis of the lysosomal enzyme, myeloperoxidase (MPO), which was linearly proportional to the degree of hyposmolarity between a 5 and 30% decrease (r = 0.92, p less than 0.001). Cell viability was unaffected by the hyposmolarity. The kinetics of MPO exocytosis induced by opsonized zymosan (OZ) and hyposmolarity were indistinguishable; the combination of hyposmolarity and OZ was additive. Since hyposmolarity similarly stimulates a burst of hormone secretion by perifused adenohypophyseal and pancreatic islet cells, the authors suggest that hyposmolarity-induced exocytosis is a general cellular phenomenon.
Sato
N
N
Department of Medicine, Oregon Health Sciences University, Portland 97201.
Wang
X B
XB
Greer
M A
MA
D002470:Cell Survival; D003571:Cytochalasin B / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D009504:Neutrophils / Q000201:enzymology*; D009994:Osmolar Concentration; D009195:Peroxidase / Q000378:metabolism*
D003571:Cytochalasin B; D009195:Peroxidase