Open AccessIn vivo administered reserpine increases piecemeal degranulation in rat adrenal chromaffin cells
Author(s) -
Crivellato Enrico,
Belloni Anna,
Nico Beatrice,
Nussdorfer Gastone G.,
Ribatti Domenico
Publication year - 2006
Publication title -
the anatomical record part a: discoveries in molecular, cellular, and evolutionary biology
Language(s) - English
Resource type - Journals
eISSN - 1552-4892
pISSN - 1552-4884
DOI - 10.1002/ar.a.20280
Subject(s) - reserpine , granule (geology) , degranulation , vesicle , cytoplasm , secretion , medicine , endocrinology , biology , chemistry , microbiology and biotechnology , ultrastructure , membrane , biochemistry , anatomy , paleontology , receptor
Abstract The effects of the amine‐depletory agent reserpine have been evaluated by transmission electron microscopy in chromaffin cells of the rat adrenal glands. The drug has been injected intraperitoneally in the animals at a dose of 0.5 mg/kg body weight in two administrations at 24‐hr interval. The observed ultrastructural changes closely reminded of piecemeal degranulation (PMD), a slow and long‐lasting secretory process previously described in normal and tumor pheochromocytes. Both adrenaline‐ and noradrenaline‐storing cells presented the following microscopic features: high granule polymorphism, due to coexistence in the same cell of normal resting granules, granules with partially mobilized components, and large empty containers; absence of granule fusion; characteristic “haloed” pattern of residual secretory contents; great amount of 30–150 nm diameter, membrane‐bound, electron‐dense and ‐lucent vesicles, free in the cytoplasm or attached to granules; and multiple vesicles budding from the granule‐limiting membranes. Morphometric analysis revealed that the frequency of all these microscopic parameters was found to be significantly increased in adrenal chromaffin cells from reserpinized rats in comparison to cells from control animals. These data suggest that reserpine, besides blocking the inward transport of catecholamines in chromaffin granules, might also stimulate a complex secretory reaction, which shares many common passages with bona fide PMD. © 2006 Wiley‐Liss, Inc.