Inosine inhibits ConA-induced hepatocyte apoptosis in vivo. Tissue sections of liver taken from A3R^+/+ (A-C) and A3R^-/- (D-F) mice 24 hours after injection with ConA (A,D), inosine (B,E), and ConA plus inosine (C,F) were assessed for apoptosis by staining single-strand breaks in nuclear DNA to detect apoptotic cells (TdT assay). This figure shows that inosine protected A3R^+/+, but not A3R^-/-, liver from ConA-induced damage by inhibiting hepatocyte apoptosis. Original magnification, × 10.