Malathion is one of the organophosphorus insecticides least toxic to mammals. The toxicity of this compound in chick embryos is known; however, its teratogenic nature has not been recorded. Concentrations from 1.17 to 116.6 milligrams per egg were injected into the yolk sacs of 1 to 12 day incubated chicken eggs, and various types of abnormalities were produced. Injections of 3.99 and 6.42 milligrams malathion into the yolk sacs of 4 and 5 day incubated eggs produced deformed chicks with a combination of sparse plumage, micromelia, overall growth retardation and beak defects.All known breakdown and related products of malathion were investigated as to their teratogenicity; however, only the parent compound and malaoxon were capable of producing the aforementioned terata. Malathion causes a reduction in growth to, embryos from eggs injected on days 4 and 5 of incubation. Various metabolites were injected along with malathion into fertile eggs in an attempt to determine the possible effect of the latter compound on metabolism. Of the compounds injected, tryptophan prevented both the malformations and the growth retardation while nicotinamide, nicotinic acid, and quinolinic acid prevented the malformations only. A tryptophan assay revealed a reduction of total tryptophan content in malathion treated embryos indicating a reduction in uptake of this amino acid from the yolk. Other compounds related to tryptophan by electronic reactivity enhanced the effect of malathion. Several NAB or NADp linked dehydrogenasas were investigated by histochemical and biochemical methods on both malathion treated and untreated embryos. A cholinesterase assay on embryo homogenates revealed no apparent relationship between cholinesterase levels and teratisms.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/10790 |
| Date | January 1971 |
| Creators | Greenberg, Jack. |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 267 p. |
Page generated in 0.0025 seconds