Study on the physiological function of bombyxin

1. 我们制备了多种抗合成蚕蛹毒素的小鼠单克隆抗体，并建立了一种时间分辨荧光免疫法（TR-FIA）检测蚕蛹毒素。该方法具有灵敏度高、操作简便、安全、省时等优点。利用TR-FIA检测了家蚕幼虫-蛹-成虫发育过程中血淋巴中家蚕素滴度的变化。幼虫期滴度低，蛹期前期和中期滴度高。只在雄虫羽化后立即观察到滴度急剧上升。羽化后血淋巴脂质也仅在雄性中增加，提示蚕蛹毒素可能参与了脂质代谢的调节。我们对家蚕幼虫中蚕蛹素的生理功能进行了研究，得到以下结果：蚕蛹素具有低海藻活性。2)蚕贝素增加了中肠和被膜（包括肌肉）的海藻化酶活性。3)蚕贝素对脂肪体海藻糖合成酶活性无影响。4)蚕豆素降低脂肪体中糖原含量。这些结果表明，蚕豆素调节糖和脂质代谢，在变态过程中起重要作用。

1. We produced many kinds of mouse monoclonal antibodies against synthetic bombyxin-II and developed a time-resolved fluoroimmunoassay (TR-FIA) for bombyxin. This assay method is superior to the conventional radioimmunoassay in sensitivity, simplicity, safety and time-saving.2. Using TR-FIA,we examined the changes in bombyxin titer in hemolymph during larva-pupa-adult development of the silkmoth, Bombyx mori. The titer was low in the larval stage, while high in the early and middle pupal stages. A steep rise in the titer was observed immediately after eclosion only in males. Hemolymph lipid also increased after eclosion only in males, suggesting a possibility that bombyxin is involved in the regulation of lipid metabolism.3. We investigated the physiological function of bombyxin in Bombyx larvae and obtained the following results.1) Bombyxin has a hypotrehalosemic activity.2) Bombyxin increases the trehalase activity in the midgut and integument (including muscles).3) Bombyxin has no effect on trehalose synthase activity in the fat body.4) Bombyxin decreases glycogen content in the fat body.These results suggested that bombyxin regulates sugar and lipid metabolism and that bombyxin plays an important role (s) in the process of metamorphosis.