棉铃虫及粘虫肠中咽侧体静止激素样活性物质对咽侧体活性的影响

利用放射化学的方法分别检测了棉铃虫Helicoverpaarmigera、粘虫Mythimnaseparata幼虫和成虫肠中咽侧体静止激素 (allatostatin ,AS)样的活性物质。发现在棉铃虫、粘虫幼虫和成虫肠中均存在的AS样活性物质 ,可以在体外抑制咽侧体 (corporaallata,CA)的保幼激素 ( juvenilehormone,JH)的生物合成。生物测定的结果表明 ,粘虫幼虫肠中AS样活性物质的含量较棉铃虫的高 ;粘虫 1个幼虫肠当量对CA的JH合成的抑制率达 4 3% ,而棉铃虫幼虫肠只有 2 6%。无论是棉铃虫还是粘虫 ,雌成虫中肠对CA的抑制比雄成虫中肠的高 ,后肠对CA的JH合成的抑制明显的低于中肠对CA的抑制。中肠对CA的JH合成的抑制是可回复的。中肠粗提物经蛋白酶水解后对CA合成JH的抑制率降低 ,表明肠中AS样的活性物质是肽或蛋白质

Effect on the corpora allata activity of allatostatin-like material from the gut of Helicoverpa armigera and Mythimna separata

In this study the ability of gut extracts from the larva and adult of cotton bollworm, Helicoverpa armigera and armyworm, Mythimna separata to inhibit juvenile hormone (JH) synthesis was tested in vitro by radiochemical assay. The allatostatin (AS) like material that can inhibit JH synthesis in corpora allata (CA) occurred in the larvae and adult guts of these two species of insects. The inhibition of JH synthesis by 1 gut equivalent extract from larvae M.separata (43%) was greater than that from H.armigera (26%). Using 5 midgut equivalent of female or 10 midgut equivalent of male, the inhibition of JH synthesis achieved about 47% for the cotton bollworm and 35% for the armyworm. This indicates that the content of AS like material in the gut from female is higher than that from male in both H.armigera and M.separata. The inhibition of JH synthesis of CA was significantly higher by midgut extract than by hindgut extract in both insects. The inhibition of CA activity by midgut extract was completely reversible, and the midgut extract from M.separata was sensitive to trypsin and chymotrypsin.