| Anabasine, nicotine, and coniine are plant alkaloids that mimic acetylcholine. Both coniine and nicotine are known teratogens. Coniine is hypothesized to cause malformations via its action on acetylcholine receptors. If the toxic and teratogenic mechanisms are the same, the malformations caused by these three chemicals should be the same within a species. I tested this hypothesis by comparing the teratogenic effect of the three alkaloids on developing chick embryos and on Drosophila melanogaster larvae. Chicken eggs were injected with anabasine, nicotine, or coniine suspended in corn oil. Concurrent controls were run. The eggs were allowed to develop until day 17, when the embryos were weighed and examined for malformations. The cartilage and bone were examined and measured. All three alkaloids caused arthrogryposis in the chick embryo and significantly reduced embryo size relative to controls. Bone size was correlated with embryo weight and was not otherwise affected by treatment. Anabasine-dosed chicks had a marginally significantly higher malformation rate than controls. Coniine and nicotine treatment produced malformations at a significantly higher rate than controls. Nicotine and anabasine treatment produced an additional previously unreported malformation, ectopia cordis..;Fruit fly larvae were exposed to each alkaloid in the diet throughout larval development. Adult flies were scored for malformations. Treated flies exhibited a variety of malformations including unequal wing length, crumpled wings, damaged terga, and asymmetry of the thorax, bent humeral bristles, and wing notches. Each alkaloid produced only one malformation at a rate that was significantly higher than control: crumpled wings for coniine, asymmetry of the thorax for nicotine, and unequal wing lengths for anabasine. My results indicate that the malformations in Drosophila melanogaster and chickens are not caused not by the neurotoxicity of the chemicals but rather via an unknown mechanism.;To elucidate the fate of coniine within the body, the feces, urine, and body tissues of house mice were examined after oral administration of a sub-lethal dose of coniine. Coniine was quickly eliminated. |
