Localization of [22,23-3H2] dihydroazadirachtin binding sites in locust (Schistocerca gregaria) testes was investigated by in vitro autoradiography. Preferential binding of the ligand at concentrations of 10-8 M was located in the testes follicles, localized on the tail portions of developing sperm. This binding was fully displaceable with an excess of unlabelled ligand. The results indicate that Azadirachtin binds preferentially to sites on the organelles associated with maturing locust sperm tails. Azadirachtin, at concentrations of 10-4 M and above, caused a time-dependent reduction in the motility of eupyrene sperm bundles liberated from the accessory glands of mature male S. gregaria, The effect of azadirachtin on boar sperm motility was also time- and concentration-dependent. Forward motility was significantly reduced by concentrations above 10-5 M at each time interval (P < 0.05).
- Azadirachta indica
- Schistocerca gregaria