Vacuole formation in the endothelium of rat extremity vessels depends on fixation techniques and vessel type

Gábor Raffai, Erzsébet Fehér, György Nádasy, Sándor Paku, Gábor Pogány, Ferenc Tímár, Béla Szende, Emil Monos

Research output: Article

3 Citations (Scopus)


Applying immersion fixation for electron microscopy, huge clear endothelial membrane-bound vacuoles of 0.1-3 μm diameter were noted in the extremity veins of Sprague-Dawley rats. Histological and electron microscopic histochemical methods were applied to determine whether they were the product of programmed cell death or any other kind of cell damage. Image analyzer was used to measure the total area of the vacuoles in the endothelium cells. Neither lipid content nor acidic phosphatase activity could be identified in the vacuoles. In saphenous and brachial veins, the vacuoles occupied 20.6±2.21% and 18±2.45% of the endothelium, respectively. Venous endothelium of two different strains of rat also contained the vacuoles. No such structures appeared in extremity arteries. Long-term tilting did not influence vacuolization. Using in vivo whole body fixation, only pinocytotic and dense microvesicles, but no vacuoles were noted. In conclusion, the clear vacuolar structures represent neither lipid inclusions nor secondary lysosomes. The method of tissue fixation is critical when venous endothelial vesicles are investigated. It is presumed that the vacuoles originated from intra- or intercellular microstructures, and that in case of the collapsible vein segments, their size is increased under the pathological-hypoxic and low-pressure-conditions of in vitro fixation.

Original languageEnglish
Pages (from-to)41-46
Number of pages6
JournalPathology Research and Practice
Issue number1
Publication statusPublished - ápr. 15 2004


ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Cell Biology

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