Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für medizinische Forschung     Collection: Abteilung Molekulare Zellforschung     Display Documents

ID: 568826.0, MPI für medizinische Forschung / Abteilung Molekulare Zellforschung
Regulation of granule size in human and horse eosinophils by number of fusion events among unit granules
Translation of Title:Regulation of granule size in human and horse eosinophils by number of fusion events among unit granules
Authors:Hartmann, Jana; Scepek, Susanne; Lindau, Manfred
Date of Publication (YYYY-MM-DD):1995-01-01
Title of Journal:Journal of Physiology
Journal Abbrev.:J. Physiol.
Issue / Number:1
Start Page:201
End Page:209
Review Status:Peer-review
Audience:Experts Only
Intended Educational Use:No
Abstract / Description:We have investigated the granule size distributions in human and horse eosinophils by time−resolved patch−clamp capacitance measurements. 2. During exocytosis of single granules the electrical capacitance of the plasma membrane increases in discrete steps. The steps in horse cells are about six times larger than those in human cells in accordance with the difference in granule size. 3. In both species a multimodal capacitance step size distribution is observed with a first peak at 6−7 fF corresponding to granules with a diameter of about 450−500 nm and a surface area of about 0.7 microns2, which we call the unit granule. The other peaks in the distributions correspond to multiples of the surface area of these units. 4. These results show that the larger granules are formed by fusion of several unit granules and the final size of mature granules is determined by the number of units allowed to fuse with each other. Whereas in human eosinophils most granules consist of one or two units, most granules of horse eosinophils are formed by fusion of seven to fifteen units. 5. The intracellular fusion events associated with vesicular traffic are believed to occur constitutively. In contrast, our results indicate that a cellular mechanism exists which regulates the size of the mature granules by determining the number of units allowed to fuse with each other. In view of our recent report that granule−granule fusion can be activated by GTP gamma S, this regulation may possibly involve GTP− binding proteins
Last Change of the Resource (YYYY-MM-DD):--
External Publication Status:published
Document Type:Article
Communicated by:Wulf Kaiser
Affiliations:MPI für medizinische Forschung/Abteilung Molekulare Zellforschung
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.