[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.
First Department of Internal Medicine, Tohoku University School of Medicine.
T
T
Aizawa
Y
Y
Kakuta
G
G
Tamura
K
K
Shirato
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