Lange A B, Chan K K, Stay B
Erindale College, University of Toronto, Mississauga, Ontario, Canada.
Arch Insect Biochem Physiol. 1993;24(2):79-92. doi: 10.1002/arch.940240203.
Diploptera punctata allatostatins are brain neuropeptides that inhibit juvenile hormone synthesis by corpora allata. They also occur in nerves of many organs other than corpora allata. The distribution of allatostatins in, and the effect of allatostatins on two other organs, antennal pulsatile organ and hindgut, are demonstrated here. Allatostatin I-like immunoreactive material is present in cells of subesophageal and terminal abdominal ganglia; these ganglia are known to contain the cells that project to antennal heart nerve and proctodeal nerve, respectively. Electron micrographs of both organs show nerve terminals with allatostatic immunoreactive granules along with terminals containing nonimmunoreactive granules. Immunoreactive neurosecretory granules are about 200 nm in largest dimension. In the antennal pulsatile organ, profiles of the nerve terminals are larger in the ampullar wall than in the muscle; in hindgut the terminals with immunoreactive granules are associated with the muscle net below the circular muscle. Hindgut responded to allatostatins I and IV with a dose-dependent decrease in amplitude and frequency of contraction that was reversible, with the threshold concentration for response between 10(-8) and 10(-7) M. In contrast, pulsatile organ muscle showed no such change with either allatostatin at 10(-7)-10(-4) M. However, both organs responded to proctolin with increased amplitude and frequency of contractions. Allatostatins I and IV inhibited the proctolin-induced increase of hindgut contraction, whereas no such effect was seen in antennal pulsatile organ muscle. Extract of antennal pulsatile organ muscle showed proctolin-like bioactivity that comigrated with authentic proctolin on three sequential HPLC systems.
点刻原伪蝎的咽侧体抑制素是一类脑源神经肽，可抑制咽侧体合成保幼激素。它们也存在于咽侧体以外的许多器官的神经中。本文展示了咽侧体抑制素在另外两个器官——触角搏动器和后肠中的分布情况，以及咽侧体抑制素对这两个器官的作用。类咽侧体抑制素I免疫反应性物质存在于咽下神经节和腹部末端神经节的细胞中；已知这些神经节分别含有投射到触角心神经和直肠神经的细胞。两个器官的电子显微镜图像均显示，神经末梢既有含咽侧体抑制素免疫反应性颗粒的，也有含非免疫反应性颗粒的。免疫反应性神经分泌颗粒的最大尺寸约为200纳米。在触角搏动器中，壶腹壁上神经末梢的轮廓比肌肉中的大；在后肠中，含免疫反应性颗粒的末梢与环肌下方的肌网相关联。后肠对咽侧体抑制素I和IV的反应是收缩幅度和频率呈剂量依赖性降低，且这种降低是可逆的，反应的阈值浓度在10^(-8)至10^(-7) M之间。相比之下，在10^(-7) - 10^(-4) M的任何一种咽侧体抑制素作用下，搏动器肌肉均未出现这种变化。然而，两个器官对促肠肌肽的反应都是收缩幅度和频率增加。咽侧体抑制素I和IV抑制了促肠肌肽诱导的后肠收缩增加，而在触角搏动器肌肉中未观察到这种效应。触角搏动器肌肉提取物显示出促肠肌肽样生物活性，在三个连续的高效液相色谱系统上与纯促肠肌肽共迁移。
