[Induction of granule release by intracellular application of Ca and GTP gamma S in human eosinophils].
The roles of Ca and G proteins in granule release from human eosinophils were examined using a patch-clamp technique in single cells. The morphological changes and the release of eosinophil peroxidase (EPO) from single cells were simultaneously observed. The intracellular application of Ca, and GTP-gamma-S induced fusion of EPO containing granules with the surface membrane which was associated with a marked increase in membrane capacitance. Ca alone caused a rapid granule release at an early stage of cell dialysis, but most granules still remained in a cluster. GTP-gamma-S alone caused a gradual degranulation. Northern blot analysis revealed the definite expression of smg p21 mRNA with no appreciable expression of smg p25A in human eosinophils.
Aizawa
T
T
First Department of Internal Medicine, Tohoku University School of Medicine.
Kakuta
Y
Y
Tamura
G
G
Shirato
K
K
D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D015550:Cell Degranulation / Q000187:drug effects*; D002478:Cells, Cultured; D047209:Eosinophil Peroxidase; D004804:Eosinophils / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D010544:Peroxidases / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020692:rab3 GTP-Binding Proteins
D012333:RNA, Messenger; D047209:Eosinophil Peroxidase; D010544:Peroxidases; D019204:GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D002118:Calcium