H-IPSE reduces bladder hemoglobin levels, but not bladder wet weight, in ifosfamide-treated mice. A) Mice were administered recombinant IL-4, H-IPSE, and the NLS mutant of H-IPSE, with or without neutralizing anti-IL-4 antibody (α-IL4), MESNA, or saline, before ifosfamide challenge. Animals were then euthanized and their bladders excised, weighed to measure bladder wet weight, and then subjected to the Drabkin’s test to measure tissue hemoglobin levels. The H-IPSE-treated group showed significantly reduced bladder hemoglobin levels compared with the ifosfamide-only group, and prior administration of neutralizing anti-IL-4 antibody reversed the effect of H-IPSE, albeit without achieving statistical significance. The NLS mutant-treated group, as well as MESNA-treated mice, did not exhibit a significant decrease in bladder hemoglobin following ifosfamide exposure. Plotted data are pooled from 3 repeat experiments (n = 3–4 each). The bars represent means and sd. B) There were no significant differences in bladder wet weights across treatment groups. Horizontal bars represent means. *P < 0.05, **P < 0.01.