Exocytosis in living salivary glands: direct visualization by video-enhanced microscopy and confocal laser microscopy.

摘要: Although exocytosis is widely believed to involve granule movement, membrane fusion and the emptying of content, direct study these processes has been difficult in living cells because limited resolution conventional light microscopy. Using video-enhanced microscopy confocal laser microscopy, we have now studied rat parotid submandibular gland acinar cells. Under a differential interference contrast (DIC) microscope equipped with CCD camera high speed image processor, secretory granules were general stationary even after stimulation isoproterenol (IPR). Following IPR stimulation, however, there abrupt changes intensity granules, many disappeared. Confocal was then performed confirm whether observed related content release. For this, perfused fluid-phase tracer Lucifer Yellow; images thus obtained clearly demonstrated appearance fluorescence omega-shaped invaginations apical plasma which corresponded sites at DIC images. The time sequence analyses showed that repetitive disappearance fluorescent foci until most depleted. During this time, did not appear be any significant expansion if endocytic uptake occurred, it below limit detection. These observations provide new insights into exocytotic process salivary glands are variance some respects previous interpretations made from electron