ISSN:
1573-6865
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The effect of monensin on the Golgi complex, formation of secretory granules and basal β-endorphin secretion in cultured melanotrophs from the rat pituitary was studied. Earlier studies on the effect of monensin on regulated secretion have generally showed only minor effects on secretory granules. The initial (within 5 min) effect of monensin on the melanotroph was the appearance of large vacuoles at the trans-side of the thiamine pyrophosphatase-positive trans-most Golgi cisternae. This was associated with a dose-dependent inhibition of the condensation of electron-dense secretory products. After 1 h of treatment with 1 μM monensin the Golgi stack was completely vacuolized. At the same time mature secretory granules were enlarged to severalfold their original size, and after 4h of treatment secretory granules were no longer observed. Despite the marked effects on granule formation and mature secretory granules monensin did not affect the basal release of β-endorphin-immunoreactive material during continued incubation for up to 4h, indicating that basal peptide secretion can bypass the monensin block.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02331379
