Accession Number : ADA300357

Title :   The Latency of Exocytosis Varies with the Mechanism of Stimulated Release in PC12 Cells.

Descriptive Note : Technical rept.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF CHEMISTRY

Personal Author(s) : Zerby, Susan E. ; Ewing, Andrew G.

PDF Url : ADA300357

Report Date : 21 SEP 1995

Pagination or Media Count : 33

Abstract : To compare the time course of different mechanisms of chemically stimulated release, amperometric detection of dopamine was carried out at single PCl2 cells. The rapid response of carbon fiber microelectrodes allowed the detection of single exocytotic events thus providing time-resolved information about the dynamics of stimulated release, in particular the latency between the stimulation of a cell arid the secretion of catecholamines. Upon rapid depolarization of the cell membrane caused by application of 105 mM K+, almost immediate (6 + or - s) release of dopamine was observed. Stimulation with 1 mM nicotine, involving the stimulant binding to a ligand-gated ion channel, resulted in a short (37 + or - 5 s) delay between stimulation and secretion. The application of 1 mM muscarine to the cells caused a long (103 + or - 11 s) latency before exocytosis was detected. A biphasic response that appeared to be similar to a combination of nicotine- and muscarine- stimulated release was observed when cells were stimulated with 10 mM acetylcholine. Thus it appears that the dynamics of stimulated release at single PC 12 cells is significantly affected by the mechanism leading to exocytosis.

Descriptors :   *CELLS(BIOLOGY), *DOPAMINE, FIBERS, QUICK REACTION, MEMBRANES(BIOLOGY), STIMULATION(GENERAL), DETECTION, DYNAMICS, DEPOLARIZATION, CATECHOLAMINES, SECRETION, MUSCARINE, NICOTINE.

Subject Categories : Medicine and Medical Research
      Toxicology

Distribution Statement : APPROVED FOR PUBLIC RELEASE