Abstract
Mouse peritoneal macrophages containing Cr-ethylenediamine tetraacetic acid-14C within pinolysosomes were prepared by in vitro culture techniques. Exposure of these cells to nicotine tartrate (13.2 mM) for 30 minutes resulted in a release of radioactivity and acid phosphatase, but not aldolase, into the culture medium. Much of the released radioactivity was derived from the sedimentable fraction of cell homogenates supporting the notion that part, at least, of the radioactivity released originated from pinolysosomes. This effect of nicotine was apparently not calcium-dependent nor was it mimicked by tetramethylammonium ion nor blocked by hexamethonium ion. Such results make it doubtful that nicotine was acting by increasing stimulus-secretion coupling. From these and other studies, it is presently hypothesized that nicotine increases exocytosis by increasing the interior membrane surface available for coalescence with pinolysosomes.
Footnotes
- Received March 9, 1972.
- Accepted June 16, 1972.
- © 1972 by The Williams & Wilkins Co.
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