Membrane Properties Involved in Calcium-Stimulated Microparticle Release from the Plasma Membranes of S49 Lymphoma Cells
Figure 3
Ionomycin-stimulated microparticle release requires calcium-activated potassium current. Cells were washed and suspended in normal MBSS (“Iono alone” or “Raji”) or in MBSS that contained EGTA (2 mM) instead of calcium, high potassium (83 mM KCl with equivalent reduction in NaCl), or quinine (1 mM) at 37°C. The normalized light scatter intensity was calculated by subtracting the average initial intensity immediately prior to ionomycin addition (20 points) from the average intensity at the plateau after ionomycin (about 350 s later; see Figure 2). This difference was then divided by the average initial intensity to standardize among trials. Differences in the normalized intensity among groups were significant by one-way analysis of variance (, –9 per group). A posttest (Dunnett’s) revealed that the group of S49 cells treated with normal MBSS was distinguishable from each of the other four ().
