title: Pancreatin-EDTA treatment affects buoyancy of cells in Cohn fraction V protein density gradients without residual effect on cell size.
abstract: The buoyancy of suspension-grown Mastocytoma P815 X-2 cells in albumin-rich Cohn fraction V protein (CFVP) density gradients was found to be affected by prior incubation of the cells in pancreatin-EDTA salt solution. Whereas in pH 5.2 CFVP, pancreatin-EDTA treated cells behaved as if of reduced density when compared with the control 'undigested' group, in pH 7.3 CFVP they behaved as if of increased density. By contrast, pancreatin-EDTA treatment had no effect on the buoyancy of mastocytoma cells in polyvinylpyrrolidone-coated colloidal silica (PVP-CS, Percoll T.M.) density gradients of either pH 5.2 or pH 7.3. As cell size determinations failed to reveal alterations in cell size either as a direct result of pancreatin-EDTA treatment or as a combined consequence of such treatment and exposure to CFVP either with or without centrifugation, a mechanism involving a change in cell density other than during the centrifugation process itself seems unlikely. Binding studies employing 125I-CFVP, although indicating that CFVP bound to cells at 4 degrees, failed to reveal a pancreatin-EDTA treatment-related difference in the avidity of this binding. Although the mechanism of the pancreatin-EDTA-induced buoyancy shift in CFVP remains obscure, the absence of such an effect in PVP-CS suggests that the latter cell separation solution may more accurately be used to determine cell density.
mesh_terms: D000818:Animals; D002452:Cell Count; D002460:Cell Line; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured / Q000187:drug effects; D002499:Centrifugation, Density Gradient / Q000379:methods*; D002500:Centrifugation, Isopycnic / Q000379:methods*; D003470:Culture Media; D004492:Edetic Acid / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D012515:Mast-Cell Sarcoma; D051379:Mice; D008811:Mice, Inbred DBA; D010194:Pancreatin / Q000494:pharmacology*; D012709:Serum Albumin
chemical_list: D003470:Culture Media; D012709:Serum Albumin; D010194:Pancreatin; D004492:Edetic Acid