Somatostatin modulation of initial fusion pores in Ca²⁺-triggered exocytosis from mouse chromaffin cells.

ABSTRACT: Somatostatin, a peptide hormone that activates G-protein-coupled receptors, inhibits the secretion of many hormones. This study investigated the mechanisms of this inhibition using amperometry recording of Ca²⁺-triggered catecholamine secretion from mouse chromaffin cells. Two distinct stimulation protocols, high-KCl depolarization and caffeine, were used to trigger exocytosis, and confocal fluorescence imaging was used to monitor the rise in intracellular free Ca²⁺. Analysis of single-vesicle fusion events (spikes) resolved the action of somatostatin on fusion pores at different stages. Somatostatin reduced spike frequency, and this reduction was accompanied by prolongation of pre-spike feet and slowing of spike rise times. This indicates that somatostatin stabilizes

SUBMITTER: Cheng J 

PROVIDER: S-EPMC11825891 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature