. Author manuscript; available in PMC: 2007 Dec 3.

Published in final edited form as: Toxicol Pathol. 2007;35(4):533–540. doi: 10.1080/01926230701338941

Table 5.

Cell labeling indices determined with PCNA immunostaining during the 13-week prechronic inhalation studies with decalin and propylene glycol mono-t-butyl ether.


Propylene glycol mono-t-butyl ether	Chamber Control	75 ppm	150 ppm	300 ppm	600 ppm	1,200 ppm
Labeling index (%) n = 5
Week 2	3.6 ± 0.1	3.6 ± 0.2	3.9 ± 0.2	3.4 ± 0.1	4.4 ± 0.2^*	5.5 ± 0.4^**
Week 6	3.6 ± 0.1	3.2 ± 0.1	3.4 ± 0.2	3.9 ± 0.1	4.3 ± 0.0^*	4.9 ± 0.3^*
Week 13	3.2 ± 0.2	3.8 ± 0.2	4.3 ± 0.2^**	4.1 ± 0.2^*	5.0 ± 0.4^**	6.6 ± 0.4^**

Decalin	Chamber Control	25 ppm	50 ppm	100 ppm	200 ppm	400 ppm

Labeling index (%) n = 5
Week 2	3.3 ± 0.2	4.2 ± 0.1^*	3.9 ± 0.3	4.3 ± 0.2^**	4.2 ± 0.3^*	4.9 ± 0.3^**
Week 6	3.2 ± 0.1	4.2 ± 0.1^**	4.8 ± 0.1^**	4.6 ± 0.3^**	5.0 ± 0.2^**	5.9 ± 0.3^**
Week 13	3.1 ± 0.2	4.5 ± 0.1^**	3.7 ± 0.3^*	4.1 ± 0.2^*	4.5 ± 0.2^**	4.5 ± 0.2^**

Significantly different (p < 0.05) from the chamber control group.

^**

p < 0.01, data are presented as mean + S.E.