Subchronic Hepatotoxicity Evaluation of 2,3,4,6-Tetrachlorophenol in Sprague Dawley Rats

Table 5

Selected histopathologic changes in the hepatocyte of male SD rats following 5 days, 2 weeks, 4 weeks, and 13 weeks of daily exposure of TCP by oral gavage.

Time point	Finding	TCP dose (mg/kg/day)
		0	10	25	50	100	200
5 days	Vac-C^1	—^6	—	—	—	—	—
	Hyp-C^2	—	—	—	—	1/10 (1.0)	10/10*** (1.0)
	Nec-C^3	—	—	—	—	1/10 (1.0)	2/10 (1.0)
2 weeks	Vac-C	—	—	1/10 (1.0)^7	1/10 (1.0)	4/10 (1.5)	7/10** (1.6)
	Hyp-C	—	—	—	4/10 (1.0)	10/10*** (2.0)	10/10*** (3.4)
	Nec-C	—	—	—	2/10 (1.0)	6/10* (1.0)	9/10*** (2.3)
4 weeks	Vac-C	—	1/10 (1.0)	4/10 (1.3)	7/10** (1.4)	9/10*** (1.7)	8/10** (1.6)
	Hyp-C	—	—	4/10 (1.0)	10/10*** (1.0)	10/10*** (2.2)	10/10*** (3.5)
	Nec-C	—	—	—	7/10** (1.0)	9/10*** (1.3)	9/10*** (2.4)
13 weeks	Vac-C	4/12 (1.0)	9/10 (1.6)	9/9* (2.4)	9/9* (3.4)	10/10** (4.3)	10/10** (4.7)
	Hyp-C	—	4/10 (1.0)	8/9*** (1.3)	9/9*** (2.6)	—	—
	Hyp-D^4	—	—	—	—	10/10*** (3.0)	10/10*** (4.2)
	Nec-C	—	—	—	3/9 (1.0)	2/10 (1.5)	—
	Nec-M^5	—	—	—	—	1/10 (1.0)	10/10*** (2.3)

¹Vac-C: vacuolation (centrilobular).
²Hyp-C: hypertrophy (centrilobular).
³Nec-C: necrosis, single cell (centrilobular).
⁴Hyp-D: hypertrophy (diffuse).
⁵Nec-M: necrosis, single cell (midzonal).
⁶— indicates no finding.
⁷Incidence: number with finding/number examined (average severity score where 1: minimal, 2: slight/mild, 3: moderate, 4: moderately severe, 5: severe/high).
* 𝑃<0.05 compared to control.
** 𝑃<0.01 compared to control.
*** 𝑃<0.001 compared to control.