The possibleprincipal function of neurohypophysial hormones

从海洋环境到稀释环境的适应是生命史上最戏剧性的进化转变之一。这种适应已经在多个谱系中进化，但对机制的研究仅限于那些使用进化先进的后口动物（脊索动物）和蜕皮动物（甲壳动物）的研究。在这里，我们研究了先进的Lophotrochozoa/软体动物，其他未开发的类群，其可能的监管byprospersin/催产素超家族肽已知的流体稳态在脊索动物和节肢动物的体液稳态牵连。血淋巴的渗透和离子状态在广盐性头足类动物（章鱼ocellatus）从正常海水（30 ppt）转移到低（20 ppt）盐度表明hyperosmo和hyperiono的调节能力超过1周，在甲壳类和硬骨鱼。虽然通气频率下降了1天，Na+/K+-ATP酶活性，这已牵连在离子转运一般，诱导在两个后鳃后1周。此外，章鱼静脉内注射1或100 ng/g的章鱼加压素或头孢菌素，头足类动物加压素/催产素直向同源物。1天后，章鱼加压素，而不是头孢菌素，降低血淋巴渗透压和钙浓度以及尿钠浓度。这些数据为超离子调节机制的趋同进化和保守分子的协调提供了证据。

Acclimation from marine to dilute environments constitutes among the most dramatic evolutionary transitions in the history of life. Such adaptations have evolved in multiple lineages, but studies of the mechanisms are limited to those using evolutionarily advanced Deuterostome (chordates) and Ecdysozoa (crustaceans). Here we examined the body-fluid homeostasis in the advanced Lophotrochozoa/mollusc, the other unexplored taxa, and its possible regulations byvasopressin/oxytocin superfamily peptides known to be implicated in fluid homeostasis in Chordata and Arthropoda. The hemolymph osmotic and ionic status in the euryhaline cephalopod (Octopus ocellatus) following transfer from normal seawater (30 ppt) to low (20 ppt) salinity indicate the hyperosmo- and hyperiono-regulatory abilities for more than 1 week, as in crustaceans and teleost fish. While ventilation frequency decreased by 1 day, Na+/K+-ATPase activity, which has been implicated in ion transport generally, was induced in two of the eight posterior gills after 1 week. Furthermore, the octopuses were intravenously injected with 1 or 100 ng/g octopressin or cephalotocin, cephalopod vasopressin/oxytocin orthologs. After 1 day, octopressin, not cephalotocin, decreased the hemolymph osmolality and Ca concentrations as well as urinary Na concentrations. These data provide evidence for convergent evolution in the hyper-ionoregulatory mechanisms and the coordination by conserved molecules.