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Alternative pathways of apoptosis induced by methylprednisolone and valinomycin analyzed by flow cytometry

Citation

Deckers, CL and Lyons, AB and Samuel, K and Sanderson, A and Maddy, AH, Alternative pathways of apoptosis induced by methylprednisolone and valinomycin analyzed by flow cytometry, Experimental Cell Research, 208, (2) pp. 362-370. ISSN 0014-4827 (1993) [Refereed Article]

Copyright Statement

Copyright 1993 by Academic Press, Inc. All rights of reproduction in any form reserved.

DOI: doi:10.1006/excr.1993.1257

Abstract

Apoptosis of murine thymocytes induced by either methylprednisolone or valinomycin was studied by flow cytometry. The apoptosis induced by methylprednisolone followed three stages: an initial decrease in cell volume, indicated by a fall in forward scatter accompanied by faint ethidium bromide staining, a second stage in which the cells became brightly stained by ethidium bromide, and a final stage when the cells were apparently less fluorescent as the nuclei disintegrated into apoptotic bodies. As the forward scatter of cells decreased there was a simultaneous depolarization of the cells and an elevation of intracellular calcium. These early changes preceded the fragmentation of the DNA which also preceded the intense staining of the cells by ethidium bromide. Methylprednisolone-induced apoptosis was inhibited by low concentrations (1 x 10(-7) M) of valinomycin and nonactin, neither of which could themselves induce apoptosis at these low concentrations. Cadmidazolium and cycloheximide arrested the program at an early stage. Okadaic acid allowed volume loss and ethidium bromide staining to proceed in the absence of DNA fragmentation. At high concentrations (1 x 10(-5) M) valinomycin induced a form of apoptosis, but nonactin only caused the cells to fragment. The valinomycin-induced apoptosis, although it involved the degradation of DNA and the disintegration of the nuclei into apoptotic bodies, differed from the methylprednisolone apoptosis as it did not involve a decrease of cell volume and was not inhibited by cycloheximide or affected by okadaic acid.

Item Details

Item Type:Refereed Article
Keywords:Apoptosis pathway
Research Division:Medical and Health Sciences
Research Group:Immunology
Research Field:Cellular Immunology
Objective Division:Health
Objective Group:Other Health
Objective Field:Health not elsewhere classified
Author:Lyons, AB (Dr Bruce Lyons)
ID Code:113005
Year Published:1993
Web of Science® Times Cited:43
Deposited By:Medicine (Discipline)
Deposited On:2016-12-07
Last Modified:2017-05-12
Downloads:0

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