昆虫神经肽类激素的研究及应用前景

由昆虫脑神经内分泌细胞分泌的神经肽类激素 ,咽侧体活化激素 (allatotropin ,AT)和咽侧体抑制激素 (al latostatin ,AS) ,分别刺激或抑制咽侧体的保幼激素的生物合成 ,从而控制昆虫的生长、发育和变态。利用昆虫神经内分泌的失调 ,使其体内激素水平失调 ,来达到控制害虫的目的。     

Effects of vasoactive intestinal polypeptide,substance P, 5-hydroxytryptamine,met-enkephalin and neurotensin on the swimbladder smooth muscle of two teleost species,Gadus morhua andAnguilla anguilla

The effects of vasoactive intestinal polypeptide (VIP), substance P (SP), 5-hydroxytryptamine (5-HT), neurotensin (NT) and met-enkephalin (mEnk) on the smooth muscles of the teleost swimbladder were studied in two teleost species, the Atlantic cod (Gadus morhua) and the eel (Anguilla anguilla). The study was made on isolated strip preparations of the muscularis mucosae, using putative transmitters corresponding to the immunoreactive materials that have previously been localized by immunohistochemical methods in nerves or endocrine/paracrine cells of the teleost swimbladder and/or the gastrointestinal canal. VIP was relaxatory on both cod and eel swimbladder smooth muscle, SP and 5-HT were constrictory in both species, and mEnk was excitatory on the eel swimbladder smooth muscle. Clear effects of these agents were usually seen at a concentration ofca. 10 nM in cumulative concentration/effect experiments. NT had no effect in either species. In the eel, the effects on the pneumatic duct were generally greater than on the swimbladder proper. The study indicates that the 5-HT and peptides previously observed by immunohistochemistry have physiological functions in the swimbladder.     

Advances in the application of neuropeptides in insect control

The development of a new approach for the generation of a novel type of putative insect control agents based on backbone cyclic peptidomimetic antagonists of insect-neuropeptides is reported. The approach, termed the backbone cyclic neuropetide based on autogonist (BBC-NBA) was applied to the insect pyrokinin/pheromone biosynthesis activating neuropeptide (PBAN) family as a model, and led to the discovery of a potent linear lead antagonist and several highly potent, metabolically stable BBC peptidomimetic antagonists, devoid of agonistic activity, which inhibited in vivo PBAN-mediated activities in moths.     

Androgen-induced neural plasticity and the regulation of electric-social behavior in the brown ghost knifefish: current status and future directions

The weakly electric brown ghost knifefish (Apteronotus leptorhynchus) modulates its electric organ discharge to produce intraspecific communication signals called chirps. Although males and females are known to produce chirps during courtship and spawning, they show clear sex differences in their propensity to chirp in response to artificial electrosensory stimuli; males consistently chirp, whereas females generally do not. This species also shows prominent sex differences in substance P-like immunoreactivity (SPl-ir) in brain. Males, but not females, have intense SPl-ir in a number of forebrain regions known to control reproductive functions, including the prepacemaker nucleus (PPn), the command center for chirping behavior. However, androgen treatment enhances both chirping behavior and brain SPl-ir in females. In addition, chirps produced by androgen-treated females are similar to those reported to occur during spawning. The results suggest that steroid-induced neural plasticity of SPl input to the PPn may play an important role in modulating female chirping activity. However, potential problems with this interpretation are discussed.     

珍贵绢丝昆虫天蚕FXPRLamide家族神经肽的免疫组织化学鉴定

 利用Zooblotting、酶联免疫吸附测定（ELISA）和免疫组织化学等方法，对天蚕的DH、PBAN等FXPRLamide家族神经肽进行鉴定。结果表明，标记的蓖麻蚕的DH-PBAN cDNA片断能够与天蚕、樟蚕、柳蚕和棉铃虫的基因组DNA结合。这证明了天蚕可能存在FXPRLamide家族神经肽中的DH－PBAN基因；天蚕的咽下神经节中FXPRLamide神经肽含量最高，咽下神经节有三簇细胞合成FXPRLamide神经肽，在胸神经节和腹神经节也有明显的阳性细胞；天蚕5龄幼虫的血淋巴中FXPRLamide神经肽含量比较稳定，化蛹前含量升高，蛹期含量降低。上述结果证明天蚕含有DH、PBAN等FXPRLamide家族神经肽，其对天蚕的滞育和性信息素合成等的调控还需要进一步研究。     

Control of gallbladder motility in the rainbow trout,Salmo gairdneri

Immunohistochemistry revealed nerves containing VIP-like and 5-HT-like material in both gallbladder wall and bile duct of the rainbow trout, while endocrine cells containing gastrin/CCK-like and substance P-like material were present in the mucosa of the bile duct and the duodenum. Fluorescence histochemistry showed adrenergic nerves close to the muscle layer of the gallbladder.Sulphated CCK8, caerulein and non-sulphated CCK8 (in this order of potency), 5-HT and acetylcholine were excitatory on isolated strip preparations, while VIP and adrenergic agonists were inhibitory. The adrenergic drugs were probably actingvia a beta-adrenergic receptor, while the effects of 5-HT and cholinergic drugs were antagonized by methysergide and atropine respectively.Electrical stimulation of the gallbladder nervesin situ failed to show any effect or under certain conditions induced a rebound effect.It is concluded that the motility control of the rainbow trout gallbladder may involve an inhibitory innervation by adrenergic and possibly VIP-releasing nerves, while 5-HT, acetylcholine and a CCK-like substance may be involved in the excitatory control.