Granger N A, Bollenbacher W E, Vince R, Gilbert L I, Baehr J C, Dray F
Mol Cell Endocrinol. 1979 Oct;16(1):1-17. doi: 10.1016/0303-7207(79)90002-9.
An in vitro method has been developed for the investigation of the regulation of juvenile hormone biosynthesis by insect corpora allata. Glands were maintained in Marks medium 19AB and JH synthesis quantified by a modified radioimmunoassay for juvenile hormone I. The radioimmunoassay is specific for JH I and exhibits approximately 12.6% cross reactivity with JH II and no cross reactivity with JH III. The assay directly measures the JH present in culture medium and has a maximum sensitivity of 50 pg JH I equivalents. Corpora allata from day 5 last instar Manduca sexta larvae were used to define the kinetics parameters of the in vitro system, including a demonstration that small groups of right and left glands synthesize equivalent amounts of juvenile hormone. The juvenile hormones synthesized were identified as juvenile hormones I and II in a ratio of 1:4, respectively. Juvenile hormone III could not be excluded as a product of the corpora allata owing to the low cross reactivity of this homolog (1.7%) in the radioimmunoassay. Corpora allata from different developmental stages exhibited synthesis rates generally consistent with predicted activity based on in vivo hormone titers with the exception of day 5 of the last instar. The variation in gland activity relative to the control of juvenile hormone titer in vivo is discussed.
已开发出一种体外方法，用于研究昆虫咽侧体对保幼激素生物合成的调节作用。将腺体置于Marks 19AB培养基中，并通过改良的放射免疫分析法对保幼激素I进行定量，以测定保幼激素的合成情况。该放射免疫分析法对保幼激素I具有特异性，与保幼激素II的交叉反应率约为12.6%，与保幼激素III无交叉反应。该分析法可直接测定培养基中存在的保幼激素，最大灵敏度为50皮克保幼激素I当量。使用来自末龄5天的烟草天蛾幼虫的咽侧体来确定体外系统的动力学参数，包括证明左右小群腺体合成等量的保幼激素。合成的保幼激素分别被鉴定为保幼激素I和保幼激素II，比例为1:4。由于该同系物（保幼激素III）在放射免疫分析法中的交叉反应率较低（1.7%），因此不能排除其作为咽侧体产物的可能性。除末龄第5天外，来自不同发育阶段的咽侧体的合成速率总体上与基于体内激素滴度预测的活性一致。文中讨论了腺体活性相对于体内保幼激素滴度控制的变化情况。
