Pertussis toxin does not affect the time course of exocytosis in mast cells stimulated by intracellular application of GTP‐γ‐S

[摘要]

Exocytosis was studied in single rat peritoneal mast cells. Granule fusion was monitored by time-resolved capacitance measurements using the patch-clamp technique. Intracellular stimulation of mast cells with 20 μM GTP-γ-S stimulates exocytosis with a calcium-dependent time course. Secretion in response to receptormediated stimulation with compound 48/80 was completely abolished by treatment with pertussis toxin (IAP) at 180 ng/ml for 4 h. The time course of exocytosis in response to GTP-γ-S remained unaffected in IAP-treated cells supporting the involvement of a second GTP-binding protein in stimulus-secretion coupling.

[学科分类] 生物化学/生物物理

[关键词] Mast cell;Exocytosis;Ce2+;G-protein;Islet-activating protein;Patch-clamp;(Pertussis toxin);IAP;islet-activating protein;GTP;guanosine 5′-triphosphate;GTP-γ-S;guanosine 5′-O-(3-thiotriphosphate)