Hb metabolites and TNFα in CSF from rabbit pups following IVH. OxyHb (A), metHb (B), and TNFα (D) were quantified in intraventricular CSF at 24 (n = 6), 48 (n = 6), and 72 (n = 10) hours, as described in the Methods section, and the ratio of oxyHb/metHb was calculated (C). Horizontal lines depict median values. Median values of metHb and TNFα were increased at 72 hours as compared to corresponding values at 24 and 48 hours (P <0.01, Mann–Whitney U). The correlation between TNFα and metHb (E) at 72 hours was determined by linear regression analysis (r2 = 0.896, P <0.001). CSF, cerebrospinal fluid; Hb, hemoglobin; IVH, intraventricular hemorrhage; metHb, methemoglobin; oxyHb, oxyhemoglobin.