Factors governing the toxicity of putative synaptic transmitters and their analogues when injected into the haemocoel of adult maleLucilia sericata

摘要

AbstractAcetylocholine, arecoline, 2‐(dimethylamino)ethyl acetate, L‐glutamic acid, L‐4‐methyl‐eneglutamic acid, (±)‐quisqualic acid, 4‐aminobutyric acid, and dicrotophos were injected into the haemocoel of adult male Lucilia sericata. Large doses of the putative transmitters and their analogues were required for toxicity. The water soluble organo‐phosphate dicrotophos was much more toxic than any of the other compounds. Electrophysiological experiments indicated that the putative transmitters were reaching their presumed site of action in the nervous system and that their toxicity could be correlated with the intensity and duration of their effect at this site. Biochemical measurements of the rate of loss of the putative transmitters from the haemolymph indicate that, in vivo, the test insect possesses efficient mechanisms for removing these compounds from the system being studied. It is concluded that the low toxicity of the putative transmitters, which are presumed to interact reversibly with post synaptic receptor sites, may be largely due to their rapid removal from the system, resulting in a rapid fall in concentration at t