Ryanodine insects affected

Flubendiamide, a benzenedicarboxamide insecticide, also affects calcium channels. This insecticide induces unique symptomology in poisoned insects, showing a gradual contraction of the insect body. It is believed that flubendiamide induces intracellular Ca2+ release mediated by a calcium channel such as the ryanodine receptor resulting in the contraction of insect muscle (Tohnishi et al., 2005 Ebbinghaus-Kintscher et al., 2006 Nauen, 2006). 

Last but not least, it was also shown that fiubendiamide and its sulfoxide are specihc to insect ryanodine receptors and do not affect mammalian ryanodine receptors. Even high concentrations of fiubendiamide sulfoxide applied on differentiated mouse muscle C2C12 cells which express the muscle Subtype 1 and Subtype 111 did not either elicit Ca signals nor did they prevent the Ca transients elicited by caffeine (Figure 9). Therefore, we conclude that fiubendiamide and related compounds do not affect mammalian RyR Type I and III. These observations provide a good explanation for the excellent toxicological profile observed in the case of fiubendiamide. 

Quinolizidine alkaloids are found in many species of the Fabaceae, Ber-beridaceae, Leguminosae, and Solanaceae and are derived from lysine (67, 68). Some quinolizidine alkaloids are very toxic insecticides that have the potential of commercial use for the control of insects. For example, the alkaloid ryanodine, which is found in the stems and roots of Ryania speciosa, is effective as both an insect contact and stomach insecticide and is particularly effective against Lepidoptera. It has been used to control the codling moth without affecting parasites and predators of the moth (69). 

---