ISSN:
1432-2307
Keywords:
Stoma
;
Stigma
;
Myoendothelial hernia
;
Diapedesis
;
Permeability
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Perfusion of arteries with dilute silver nitrate produces in the endothelium (a) a pattern of pericellular black lines, which we earlier interpreted as a marker of the physiological electrolyte pathway (Zand et al. 1982), and (b) focal black deposits on or between the cells, either ring-shaped (stomata) or solid (stigmata). The purpose of this study was to clarify the nature and significance of these controversial structures. A glutaraldehyde-fixednormal rat aorta was perfused with silver nitrate; 17 typical stomata and stigmata were photographeden face, then studied on ultrathin serial sections. When seenen face, they fell into three groups: (I) 4 stomata in endothelial cells; (II) 6 stigmata in endothelial cells; (III) 7 stigmata on intercellular junctions. By electron microscopy, (I) all thestomata in endothelial cells corresponded to myoendothelial herniae. (II) Of the 6stigmata in endothelial cells, 4 corresponded again to myoendothelial herniae, 2 corresponded to blebs (it seemed likely that these blebs had existedin vivo, but the possibility of a fixation artefact could not be excluded). (III) Of the 7stigmata on intercellular junctions, one corresponded to the diapedesis of a mononuclear cell; the other 6 did not correspond to visible endothelial changes and are best interpreted as points of normally higher permeability. We conclude that stomata and stigmata (under the conditions of our experiments) can be explained in at least 4 different ways, depending in part on their location (in cells, on junctions). These ancient terms therefore remain useful for descriptive purposes, as long as it is realized that their significance in any given case must be determined by electron microscopic study.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00739964
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