Time-course and Hg2+inhibition of osmotic swelling of polymorphonuclear granulocytes. (A) Time course and Hg2+ inhibition of osmotic swelling of polymorphonuclear granulocytes (PMNs) that were incubated for 3 hours at 37°C either in the absence (control) or presence of lipopolysaccharide (LPS). Cells were then transferred to a hypotonic solution and changes in size were measured by videomicroscopy (see Materials and methods). Where indicated, PMNs were incubated for 5 minutes in buffer containing 0.3 mM HgCI2, followed by swelling in the presence of HgCI2 (LPS + HgCI2). After incubation for 5 minutes in 0.3 mM HgCI2, other PMNs were then incubated for 15 minutes in buffer containing 5 mM β-mercaptoethanol and swelling was monitored in the presence of β-mercaptoethanol (LPS + HgCI2 + β-merc). Cells were assumed to have a spherical shape with a diameter calculated as the average of the maximum and minimum dimensions of each cell. *P <0.05, ***P <0.001 from control by two-way analysis of variance for repeated measures followed by Bonferoni’s post-hoc test. (B) Microscopy photographs of the time course and osmotic swelling of PMNs (original magnification ×80).