Table 1

COX-2 immunohistochemical staining of tongue lesions in rats given 10 ppm 4-NQO in their drinking water for 24 weeks

Tongue lesionsIncidence (%)No. of lesions examinedStaining with COX-2 antibodya
No. of lesions (%)
±++++++
Hyperplasia22 /33 (66.7)29014 (48.3)14 (48.3)1 (3.4)0
Dysplasia21 /33 (63.6)360011 (30.6)20 (55.6)5 (13.9)
Papilloma10 /33 (30.3)11006 (54.5)5 (45.5)0
SCC11 /33 (33.3)13005 (38.5)6 (46.2)2 (15.4)
  • a Staining: −, negative; ±, less than 10% of the area weakly positive; +, weakly positive; ++, moderately positive; +++, strongly positive.