Figure 3.

HO-1⁺ cells are increased with aging in the perivenous liver region. (A) Representative micrographs of HO-1 immunostaining in liver samples from young and old rats under control conditions and at 2 and 24 hours after heat stress. HO-1⁺ nonparenchymal cells are indicated by an arrowhead and HO-1⁺ hepatocytes are indicated by arrows. (B) Quantitation of the number of nonparenchymal HO-1⁺ cells per microscopic field. Results are presented as mean + SE; n = 3–4 animals per group (except in the old 2-hour group, where n = 2). *Significant difference between young and old animals within a time point. α: p = .063 young versus old. HO-1, heme oxygenase-1.