FIG. 4.

LDH release from infected I/St and A/Sn macrophages. The deaths of peritoneal (A) and lung (B) macrophages were assessed by specific LDH release into culture supernatants using a Promega CytoTox 96 kit. The percent specific cytotoxicity was calculated as described in Materials and Methods. The results are means ± SDs from three independent 72-h experiments. Statistically significant (P < 0.01 to 0.001; Wilcoxon test) interstrain differences are marked with asterisks. Very similar results were obtained in 48-h experiments.