Record Details
Selected aspects of the pharmacodynamics of malathion in Cancer magister Dana
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Selected aspects of the pharmacodynamics of malathion in Cancer magister Dana |
| Names |
Lebsack, Stephen Grant
(creator) Caldwell, Richard S. (advisor) |
| Date Issued | 1977-03-11 (iso8601) |
| Note | Graduation date: 1977 |
| Abstract | The metabolism of malathion in vivo was studied by injection of adult male Dungeness crab, Cancer magister, with 0.75 [mu]g/g wet weight [³H] malathion. At selected times within 24 hours of injection, subsamples of three crabs were taken for analysis of malathion and metabolites. Malathion was extensively activated by oxidative desulfuration to malaoxon, and hydrolyzed to various water soluble metabolic products. Hydrolysis appeared to be promoted by two distinct enzyme types: carboxylesterases and phosphbtriesterases. An attempt was made to study the oxidative desulfuration of malathion in vitro using preparations from crab hepatopancreas and, as a reference, rat liver. Appreciable malathion desulfurase activity was detected in the rat, but no conversion of malathion to malaoxon was observed in crab hepatopancreas. The condition and content of cytochrome P450, a primary component in the desulfurase system, was examined by difference spectrometry. Substantial P450 was detected in crab hepatopancreas, 0. 272 nM/mg microsomal protein. Anomalies in the absorption spectrum, however, indicated that the cytochrome may have partially existed as a nonfunctional derivative, cytochrome P420. It was suggested that contamination of microsomes during preparation by bile salts naturally occurring in hepatopancreas may have been responsible for denaturation of the oxidative enzymes in vitro. The studies reported here indicate that the decapod C. magister is capable of the same metabolic conversions of malathion that have been demonstrated for other classes and phyla of organisms. |
| Genre | Thesis/Dissertation |
| Topic | Malathion |
| Identifier | http://hdl.handle.net/1957/22484 |
