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https://ntp.niehs.nih.gov/go/9826

Toxic equivalency factor evaluation ((PCB 126) 3,3',4,4',5-pentachlorobiphenyl): Target Organs and Levels of Evidence for TR-520

Toxicology and Carcinogenesis Studies of 3,3',4,4',5-Pentachlorobiphenyl (PCB 126) (CASRN 57465-28-8) in Female Harlan Sprague-Dawley Rats (Gavage Studies)

Chemical (Study Title)
CASRN		Peer Review DateRoute/Exposure LevelsStudy Laboratory
Toxic equivalency factor evaluation ((PCB 126) 3,3',4,4',5-pentachlorobiphenyl)
57465-28-8		02/17/2004Gavage
FEMALE RATS ONLY: PCB-126 -- 0, 10, 30, 100, 175, 300, 550, OR 1000 NG/KG; 100/DOSE		Battelle Columbus Laboratory

Levels of Evidence

Female Rats: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: CHOLANGIOCARCINOMA 0/53 0/55 1/53 0/53 5/53 6/51 22/53 2/50 OR ADENOMA 1/53 2/55 1/53 0/53 2/53 4/51 7/53 0/50 OR HEPATOCHOLANGIOMA 0/53 0/55 0/53 0/53 0/53 0/51 3/53 0/50
  • Lung: CYSTIC KERATINIZING EPITHELIOMA 0/53 0/55 0/53 0/53 1/53 11/51 35/51 0/50 OR SQUAMOUS CELL CARCINOMA 0/53 0/55 0/53 0/53 0/53 1/51 2/51 0/50
  • Oral Cavity: GINGIVAL SQUAMOUS CELL CARINOMA (ORAL MUCOSA) 0/53 1/55 1/53 1/53 2/53 2/53 7/53 2/50
May Have Been Related
  • Adrenal Gland Cortex: ADENOMA OR CARCINOMA 0/52 2/55 1/53 0/53 1/53 1/52 4/53 3/50
  • Liver: CHOLANGIOMA 0/53 0/55 0/53 0/53 0/53 1/51 1/53 0/50
Non-Neoplastic Lesions
  • LIVER: HEPATOCYTE HYPERTROPHY; MULTINUCLEATED HEPATOCYTE; DIFFUSE FATTY CHANGE; BILE DUCT HYPERPLASIA; BILE DUCT CYST; OVAL CELL HYPERPLASIA; NECROSIS; PIGMENTATION; INFLAMMATION; NODULAR HYPERPLASIA; PORTAL FIBROSIS; CHOLANGIOFIBROSIS; TOXIC HEPATOPATHY
  • LUNG: ALVEOLAR EPITHELIUM, METAPLASIA, BRONCHIOLAR; SQUAMOUS METAPLASIA
  • ADRENAL CORTEX: ATROPHY; CYTOPLASMIC VACUOLIZATION
  • PANCREAS: CHRONIC ACTIVE INFLAMMATION; ACINAR ATROPHY; ACINAR CYTOPLASMIC VACUOLIZATION; ARTERIAL CHRONIC ACTIVE INFLAMMATION
  • KIDNEY: NEPHROPATHY; SEVERITY OF NEPHROPATHY
  • HEART: CARDIOMYOPATHY
  • THYROID GLAND: FOLLICULAR CELL HYPERTROPHY
  • THYMUS: ATROPHY; SEVERITY OF ATROPHY
  • SPLEEN: LYMPHOID FOLLICULAR ATROPHY
  • CLITORAL GLAND: CYSTIC DUCT
  • MESENTERY: ARTERIAL CHRONIC ACTIVE INFLAMMATION