1.Dogs naturally infected with Dirofilaria immitis were treated with single intravenous injections of tartar emetic, sodium antimonyl xylitol, and an aqueous suspension of antimony trioxide each prepared from radioactive antimony. Animals were sacrificed 36 hours after the injection.
2.Quantitative estimations of the antimony present in the blood after the injection of tartar emetic and sodium antimonyl xylitol showed that there was an initial rapid decrease of the element in the blood during the first hour followed by a slow removal for the next 4 to 16 hours. In some cases, there was a slight secondary rise in the blood level at 24 or 36 hours.
3.Following the injection of tartar emetic, examination of the dry tissues from 22 organs revealed that the liver contained the largest amount of antimony. The combined thyroid and parathyroid tissues contained the next largest amount. The adult Dirofilaria immitis ranked third in antimony content. It is possible that these tissues have a specific affinity for antimony since their antimony content was considerably greater than could be expected as the result of a simple distribution of a soluble compound throughout body fluids.
4.The concentration of antimony in the dermal and lymphatic tissues was of very low degree. However, other compounds are under trial and it is possible that one or more of them will be found in greater concentration in these tissues and will thus offer more promise in the treatment of such diseases as the filariases caused by Wuchereria spp. and Onchocerca volvulus.