|
|
|
|
|
|
|
||
The Journal of Cell Biology, Vol 86, 795-802, Copyright © 1980 by The Rockefeller University Press
ARTICLES |
VT Nachmias
The fine structure of resting and activated platelets was compared using two approaches novel to this dense cytoplasm. First, rapid lysis of platelets on carbon-coated grids was following by negative staining of the "cytoskeleton." Second, a brief, minimal fixation of platelets in plasma was coupled with partial lysis and examination of the unstained whole mounts at 200 kV. The results showed that the dense ground cytoplasm of discoid, fully resting platelets appeared granular or amorphous, and microfilaments were not observed. A coiled microtubule terminated in one, free, straight end. When any slight degree of activation occurred, microfilaments could be detected in the platelets. In fully spread specimens, the amorphous character of the resting cytoplasm was strikingly altered into an interconnected network of microfilaments. Stereo views of the whole mounts showed that dense granules, 100-250 nm in diameter, appeared as if suspended in the filament nets. The results support the view that platelet activation involves a major assembly of microfilaments from amorphous precursors. The change can only be seen convincingly when stringent precautions are taken during preparation because the platelets are very easily activated by thermal or mechanical stimuli.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
