Studies on osmoregulation by neurosecretory system in crustaceans

为了研究甲壳类动物中枢神经系统的渗透调节作用，采用拓扑质谱法对神经肽进行了鉴定。在小龙虾（克氏原螯虾）中，“肛门呼吸”在1880年出版的《小龙虾：动物学研究导论》一书中有描述。我们已经注意到，水在一分钟内交替进出肛门十五到十七次，似乎是由腹部第六神经节调节的。直接基质辅助激光解吸/电离与第六腹部神经节切片飞行时间质谱分析结果表明，存在orcokinin及其基因相关肽，甲壳类- sifamide，十足类速激肽相关肽，甲壳类心脏活性肽，肌抑制素样肽。这些肽在体内进行了节律性肛门收缩和肛门水通量的生物测定。在体外实验中，我们还检测了这些肽在离体小肠上的活性。每100 pmol的样品被注射到小龙虾体内，小龙虾的肛门会被十足速激肽（orcokinins）引起节律性肛门收缩。甲壳类动物心脏活性肽对肛门开放的作用最强。通过注射甲壳类促心肽或十足类速激肽观察肛门水通量。有趣的是，神经肽对离体肠的作用是多样的。后肠收缩可由后肠收缩素激活，而甲壳类促心肽或肌抑制素样肽则不能。十足快激素相关肽在直肠表现出收缩与舒张交替的重复性作用。甲壳类sifamide引起复杂的后肠运动，并诱导最有效的排便活动。我们得出的结论是，小龙虾可以从肛门吸取水分，但在腹部第六神经节中发现的神经肽的每种功能尚不清楚。我们还认为，“肛门呼吸”可能不是一种正常现象，因为这种作用可以通过过量使用甲壳类sifamide和十足类速激肽相关肽的组合来重现。少

To investigate osmoregulation by the central nerve system in crustaceans, topological mass spectrometry analysis was available for the identification of neuropeptides. In the crayfish (Procambarus clarkii), "anal respiration" has been described in the book "The Crayfish : An Introduction to the Study of Zoology" published in 1880. The observation has been noted that water is alternately taken into and expelled from the anus fifteen to seventeen times in a minute and it seemed to be regulated by the sixth abdominal ganglion. Direct matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry analysis with slice of the sixth abdominal ganglion was resulted in the presence of orcokinin and its gene-related peptides, crustacean-SIFamide, decapod tachykinin-related peptide, crustacean cardioactive peptide, myosupressin-like peptide. These peptides were examined in vivo on bioassays for rhythmic anal contraction and anal water flux. The activity of the peptides on the is … More olated intestine was also examined in vitro. Rhythmic anal contraction was caused by orcokinins, decapod tachykinin-related peptide, when each sample of 100 pmol was injected into the crayfish. Crustacean cardioactive peptide had most potent activity of anal opening. Water flux through the anus was observed by injection of crustacean cardioactive peptide or decapod tachykinin-related peptide. Interestingly, the action of the neuropeptides on the isolated intestine was diversified. The contraction of hindgut was activated by orcokinins, but not by crustacean cardioactive peptide or myosupressin-like peptide. Decapod tachykinin-related peptide showed repetitive action alternating between contraction and relaxation on the rectum. Crustacean-SIFamide caused complex movements of the hindgut, and induced most potent activity of defecation. We concluded that the crayfish can take water from the anus, but each function of neuropeptides identified in sixth abdominal ganglion remains unclear. We also think that "anal respiration" might not be a normal phenomenon, since the action was able to be reproduced by the overdose of a combination with crustacean-SIFamide and decapod tachykinin-related peptide. Less