N-methylformamide induces multiple organ toxicity in Fischer 344 rats

Area of Science:

• Toxicology
• Occupational Health
• Chemical Safety

Background:

• N-Methylformamide (NMF) is a widely used industrial chemical with increasing applications.
• Existing toxicity data for NMF is limited, with a focus primarily on hepatotoxicity.
• A comprehensive understanding of NMF's systemic toxicity is needed to establish its full toxicological profile.

Purpose of the Study:

• To evaluate the systemic toxicity of N-Methylformamide (NMF) following inhalation exposure in Fischer 344 rats.
• To identify target organs and characterize the dose-response relationship of NMF-induced toxicity.
• To determine if NMF toxicity is sex-specific.

Main Methods:

• Fischer 344 rats were exposed to 0, 30, 100, or 300 ppm NMF for 6 hours/day, 5 days/week, over 2 weeks.
• A comprehensive battery of tests was conducted, including clinical observations, body weight, food consumption, hematology, serum chemistry, organ weights, necropsy, and histopathology.
• Data analysis focused on identifying significant changes in physiological and pathological parameters across different exposure groups and sexes.

Main Results:

• NMF inhalation led to mortality in female rats at the highest exposure level (300 ppm).
• Dose-dependent decreases in food consumption and body weight were observed in both sexes at 300 ppm and in females at 100 ppm.
• Histopathological findings revealed liver and submandibular gland hypertrophy, nasal cavity injuries in both sexes, and kidney tubular basophilia predominantly in females exposed to NMF.

Conclusions:

• N-Methylformamide (NMF) exhibits systemic toxicity affecting multiple organs, including the kidneys, not solely the liver.
• NMF-related toxicity appears to be more pronounced in female rats.
• These findings contribute to the NMF toxicity profile and inform occupational safety strategies for managing NMF-related hazards.