https://ntp.niehs.nih.gov/go/LOE-TR-557

Target Organs and Levels of Evidence for TR-557

Toxicology and Carcinogenesis Studies of beta-Myrcene (CASRN 123-35-3) in F344/N Rats and B6C3F1 Mice (Gavage Studies)

Chemical (Study Title)
CASRN		 Peer Review Date Route/Exposure Levels Study Laboratory
beta-Myrcene
123-35-3		 02/25/2009 Gavage
R&M: 0, 0.25, 0.5, OR 1.0 G/KG; 50/SEX/DOSE		 Battelle Columbus Laboratory

Levels of Evidence

Male Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Kidney Tubular Cell: Adenoma (standard evaluation) 0/50 4/50 8/50 (standard and extended evaluations) 0/50 12/50 13/50 adenoma or carcinoma (standard evaluation) 0/50 7/50 9/50 (standard and extended evaluations) 0/50 14/50 13/50
Non-Neoplastic Lesions
  • Kidney: renal tubule, nephrosis; papilla, mineralization; severity of nephropathy; transitional epithelium, hyperplasia; inflammation, suppurative, focal
  • Nose: inflammation, chronic active
Female Rats: Equivocal Evidence
Type Organ/Tissue (Lesion)
May Have Been Related
  • Kidney Tubular Cell: Adenoma (standard evaluation) 0/50 1/50 0/50 2/50 extended evaluation 0/50 1/50 1/50 2/50 standard and extended evaluations 0/50 2/50 1/50 3/50
Non-Neoplastic Lesions
  • Kidney: renal tubule, nephrosis; nephropathy; severity of nephropathy; transitional epithelium, hyperplasia
Male Mice: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Liver: Adenoma 26/50 41/50 43/50 carcinoma 14/50 20/50 28/50 adenoma or carcinoma 33/50 44/50 48/50 hepatoblastoma 4/50 6/50 11/50 adenoma, carcinoma, or hepatoblastoma 34/50 45/50 48/50
Non-Neoplastic Lesions
  • Liver: Hepatocyte, hypertrophy
Female Mice: Equivocal Evidence
Type Organ/Tissue (Lesion)
May Have Been Related
  • Liver: Adenoma 6/50 13/50 6/50 carcinoma 1/50 7/50 2/50 adenoma or carcinoma 7/50 18/50 8/50
Non-Neoplastic Lesions
  • Liver: Hepatocyte, hypertrophy; mixed cell focus