Involvement of contractile protein in hypotonic expansion of macrophages.
The volume measurement of macrophages from rabbit lungs was carried out using an automatic computerized cell counter. The size of freshly prepared macrophages was 669 +/- 62 fl at 4 degrees C. The cell volume increased gradually when the cells were suspended in an isotonic saline solution. Cytochalasin B initially enhanced the increase in cell volume but then caused a reduction. The reduction was considered to be due to structural changes in filament network of contractile proteins. Under hypotonic conditions, cytochalasin B-treated cells showed increased osmotic fragility and reduced expansibility. The increased fragility was considered to result from impairment of the network structure. These findings of the effect of cytochalasin B on the volume change suggest that contractile proteins play a protective role in the membrane against hypotonic expansion.
D000818:Animals; D003285:Contractile Proteins / Q000502:physiology*; D003571:Cytochalasin B / Q000494:pharmacology; D066298:In Vitro Techniques; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects; D009994:Osmolar Concentration; D009996:Osmotic Fragility / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D011817:Rabbits; D013696:Temperature
D003285:Contractile Proteins; D003571:Cytochalasin B; D010042:Ouabain