Effects of medium calcium, and agents affecting cytoskeletal function, on cellular volume and morphology in liver tissue in vitro

Matteo A. Russo, Emanuela Morgante, Marco Tafani, George D V Van Rossum

Research output: Contribution to journalArticle

Abstract

The possible role of an exocytotic, vesicular mechanism in cellular volume regulation under iso-osmotic conditions has been studied in slices of rat liver. The effects of incubation conditions and agents affecting the actin cytoskeleton were examined for changes of water, ionic composition, and ultrastructure. Slices were pre-incubated at 1°C in an iso-osmotic buffered medium to induce swelling. Upon restoration to 37°C in the same medium, tissue lost water. The Na+-K+ adenosine triphosphatase (ATPase) inhibitor ouabain inhibited water extrusion of about 50%, an effect that was accompanied by the formation of characteristic vesicles in the cytoplasmic region between the Golgi apparatus and the bile canaliculi. Water extrusion in the presence of ouabain was partially inhibited by trifluoroperazine and completely inhibited when the medium was free of Ca 2+. In the presence of ouabain, brefeldin A caused a small reduction of water extrusion, whereas phalloidin and cytochalasins A, D, or E caused a marked inhibition. In these conditions there was a marked increase in size and number of cytoplasmic vesicles and a more widespread distribution of them within the cells, lacking the more specific orientation to the Golgi and canalicular regions that was seen in the presence of ouabain alone. Water extrusion was inhibited by phalloidin and cytochalasins in the absence of ouabain. In conclusion, our results are consistent with the hypothesis that iso-osmotic expulsion of water from hepatocytes can proceed partly through an accumulation of water in cytoplasmic vesicles, followed by exocytosis. This mechanism does not depend on Na+-K+ ATPase activity.

Original languageEnglish
Pages (from-to)1915-1925
Number of pages11
JournalJournal of Cellular Biochemistry
Volume113
Issue number6
DOIs
Publication statusPublished - Jun 2012

Keywords

  • cell volume
  • cytoskeletal morphology
  • hepatocyte function

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Fingerprint Dive into the research topics of 'Effects of medium calcium, and agents affecting cytoskeletal function, on cellular volume and morphology in liver tissue in vitro'. Together they form a unique fingerprint.

  • Cite this