Hepatotoxicity of Microcystin-LR in Fed and Fasted Rats
Abstract
The LD50 (25 hr; i.p.) for microcystin-LR in fed rats (122 micrograms/kg) was significantly higher than that in fasted rats (72 micrograms/ kg). At doses of 100, 150 and 200 micrograms/kg microcystin-LR, the median times to death were 31.9, 18.2 and 11.2 hr for fed rats, and 1.8, 1.7 and 1.5 hr for fasted rats. Biochemical and ultrastructural changes resulting from microcystin- LR (100 micrograms/kg, i.p.) were compared in fed and fasted rats 1 hr after injection. In both groups, liver weight and serum levels of sorbitol dehydrogenase and glucose significantly increased. Plasma membranes, isolated from livers of fed or fasted rats, exhibited similar toxin-induced changes in associated cytoskeletal elements. Liver mitochondria from toxin-treated, fasted rats exhibited complete inhibition of state 3 respiration, while those from toxin-treated, fed rats had ADP/O ratios and respiratory control indices comparable to control values. A sublethal dose of microcystin (50 micrograms/kg) afforded protection to fasted, but not fed, rats against a subsequent lethal dose (200 micrograms/kg) challenge given 72 hr later. Keywords: Phytotoxins.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 20, 1990
- Accession Number
- ADA221136
Entities
People
- George A. Miura
- Judith G. Pace
- Nancy A. Robinson
- Wade B. Lawrence
Organizations
- United States Army Medical Research Institute of Infectious Diseases