Figure 1.

Aged COX-2 Tg mice developed subclinical hepatitis. A: Human COX-1 and COX-2 protein expression in liver homogenates from WT and Tg animals at 16 and 60 weeks of age detected by Western blot and normalized with β-actin. B: qPCR analysis of COX-2 mRNA expression. COX-2 mRNA amounts were calculated as relative quantity (RQ) and normalized to the expression of 36b4 mRNA. Values represent fold change relative to COX-2 Tg 16 weeks. C: Intrahepatic PGE₂ concentration was determined by enzyme immunoassay in liver homogenates. D: Plasma levels of aspartate transaminase (AST) and alanine transaminase (ALT) were assayed spectrophotometrically E: H&E staining of liver sections of 16- and 60-week-old WT and Tg mice. Inflammatory foci are indicated with arrows. Micrographs were taken with a Color View Camera in a Vanox Olympus microscope at 20× magnification. Scale bar = 100 μm (for all images). Data are reported as means ± SD of six animals per condition. **P < 0.001 vs the corresponding matched animals. Wk, week.