Tab.4. Carcinogenicity study with N,N-dimethyl-p-toluidine in rats.

Author:	NTP 2012
Substance:	N,N-dimethyl-p-toluidine (purity: > 99%)
Species:	rat, F344/N, groups of 50 ♂, 50 ♀
Administration route:	oral, gavage
Dose:	0, 6, 20, 60 mg/kg body weight and day
Duration:	2 years, 5 days/week
Toxicity:	6 mg/kg body weight and day and above: liver: ♀: bile duct hyperplasia, ♂: eosinophilic foci ↑, spleen: haematopoiesis ↑, ♀: congestion and hypertrophy, nose: respiratory epithelium: metaplasia, ♂: hyperplasia, kidneys: ♀: nephropathy, ♂: pigmentation;20 mg/kg body weight and day and above: forestomach: ♂: hyperplasia and squamous cell papillomas, bone marrow: ♂: hyperplasia, lymph nodes: ♂: histiocytic infiltrates (Section 5.2.2)
		Dose [mg/kg body weight]
		0	6	20	60
surviving animals	♂	37/50 (74%)	37/50 (74%)	31/50 (62%)	21/50 (42%)*
	♀	33/50 (66%)	42/50 (84%)	33/50 (66%)	23/50 (46%)
tumours and pre-neoplastic lesions
liver:
hepatocellular carcinomas	♂	0/50	0/50	1/50  (2%)	6/50 (12%)*a)
	♀	0/50	0/50	0/50	4/49  (8%)*b)
hepatocellular adenomas and carcinomas	♂	0/50	0/50	2/50  (4%)	6/50 (12%)*
	♀	0/50	1/50  (2%)	1/50  (2%)	7/49 (14%)*
nose:
adenomas, transitional epithelium	♂	0/50	3/49  (6%)	2/50  (4%)	11/49 (22%)*
	♀	0/50	1/49  (2%)	0/50	2/49  (4%)
carcinomas, transitional epithelium	♂	0/50	0/49	0/50	2/49  (4%)
adenomas and carcinomas, transitional epithelium	♂	0/50	3/49  (6%)	2/50  (4%)	13/49 (27%)*
thyroid gland:
follicular adenomas	♂	1/50  (2%)	0/49	1/50  (2%)	3/49  (6%)
	♀	1/50  (2%)	1/47  (2%)	2/47  (4%)	0/45
follicular adenomas and carcinomas	♂	1/50  (2%)	2/49  (4%)	2/50  (4%)	4/49  (8%)
uterus:
stromal polyps	♀	3/50  (6%)	9/50 (18%)	4/50  (8%)	8/50 (16%)

^* p ≤ 0.05

^a) overall rate, poly-3 test p = 0.009

^b) overall rate, poly-3 test p = 0.041