Skip to Main Navigation
Skip to Page Content
COVID-19 is an emerging, rapidly evolving situation.

Get the latest public health information from CDC and research information from NIH.

U.S. flag

An official website of the United States government

Dot gov

The .gov means it's official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
https://ntp.niehs.nih.gov/go/8510

Target Organs and Levels of Evidence for TR-486

Toxicology and Carcinogenesis Studies of Isoprene (CASRN 78-79-5) in F344/N Rats (Inhalation Studies)

Chemical (Study Title)
CASRN
Peer Review Date Route/Exposure Levels Study Laboratory
Isoprene
78-79-5
12/10/1997 Inhalation
R: 0, 220, 700, OR 7000 PPM; 50/SEX/GROUP
Battelle Northwest Laboratory

Levels of Evidence

Male Rats: Clear Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Mammary Gland: FIBROADENOMA 2/50 4/50 6/50 21/50 FIBROADENOMA OR CARCINOMA COMBINED 2/50 5/50 7/50 21/50
  • Kidney Tubular Cell: (SINGLE SECTION) ADENOMA 0/50 2/50 2/50 6/50 (SINGLE AND STEP SECTION) ADENOMA 2/50 4/50 8/50 15/50
  • Testis: ADENOMA 33/50 37/50 44/50 48/50
Non-Neoplastic Lesions
  • KIDNEY: HYPERPLASIA
Female Rats: Some Evidence
Type Organ/Tissue (Lesion)
Neoplastic Lesions
  • Mammary Gland: FIBROADENOMA 19/50 35/50 32/50 32/50 MULTIPLE FIBROADENOMA 7/50 12/50 19/50 17/50
May Have Been Related
  • Brain: ASTROCYTOMA 0/50 0/50 1/50 0/50, GLIOMA 0/50 0/50 0/50 1/50, MEDULOBLASTOMA 0/50 0/50 0/50 1/50, MENINGEAL GRANULAR CELL TUMOR 0/50 1/50 0/50 1/50, MENINGEAL SARCOMA 0/50 1/50 0/50 1/50