Animal Pathology Resulting from Long-Term Exposure to Low Levels of Monomethylhydrazine
Abstract
The present experiments were designed to pursue investigation of the toxic effects of intermittent or continuous chronic exposure of monkeys, dogs, rats, and mice to lower levels of environmental MMH. These experiments demonstrated that continuous exposure of monkeys or rats at a concentration of 0.2 ppm MMH does not induce histopathological lesions at the light microscopic level. The same exposure levels and exposure periods do induce pathological lesions in livers and kidneys of dogs and livers, kidneys, and spleens of mice. Mice show hepatic, splenic, and renal tubular hemosiderosis under all conditions of exposure to MMH; however, the degree of hemosiderosis shows a doserelated pattern. The fact that the MMH exposure conditions of these experiments induce histopathological changes in dogs and mice but not in monkeys and rats is most probably explained by species susceptibility to MMH induced hemolysis and species capability for clearing the products of hemolysis. Lymphoid hyperplasia was noted in some exposed dogs; however, the limited sampling precludes definitive interpretation of this observation. The present experiments do not indicate a zero-toxicity MMH exposure level for dogs and mice. The experiments do demonstrate a striking difference in species susceptibility to MMH toxicity, and indicate tissue zero-toxicity levels for monkeys and rats as evaluated by light microscopy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1971
- Accession Number
- AD0751441
Entities
People
- D. J. Kroe
Organizations
- Air Force Research Laboratory