Physiological and biochemical study of peptides and hormones which are active in the cardio vascular and reproductive systems of octopus

1.章鱼心脏活性多肽从章鱼脑提取液中分离得到两种对心脏具有正性变时性和变力作用的多肽。通过TOF-MS和串联MS分析证实了这些多肽在全身心脏中的存在。这些多肽可能作为神经肽和/或神经激素参与章鱼心血管系统的兴奋控制。2.章鱼促性腺激素释放激素(GnRH)样肽从章鱼脑中分离到一种结构特征类似脊椎动物GnRH的多肽。该多肽具有促黄体激素释放活性。RT-PCR转录本在食道上、食道下脑、蒂复合体和视腺中表达。免疫反应阳性神经元胞体和纤维出现在控制视腺活动的基底叶。免疫组织化学染色显示腺体内的视腺神经和腺细胞。分离到的多肽可能是章鱼GnRH，它不仅作为一种神经激素，而且作为一种内分泌激素促进章鱼的生殖。3.在章鱼中分离到了加压素/催产素(VP/OT)超家族的第二个成员，作为已知的头孢菌素以外的VP/UT超家族的第二个成员。辛托素和头孢菌素的前体高度相似。结构组织是已知的VP/UT前体的典型结构：信号序列、非肽和神经物理蛋白结构域。这两种多肽在脑中的表达不同，即辛托素主要表达在与自主运动有关的食道上叶，而头孢菌素主要表达在向下腔静脉神经分泌系统发送轴突的血管运动叶。

1.Octopus cardioactive peptidesTwo peptides that showed both positive chronotropic and inotropic effects on the heart were isolated from brain extracts of Octopus minor using the systemic heart bioassay. The presence of the peptides in the systemic heart was confirmed by TOF-MS and tandem MS analysis. These peptides might be involved in excitatory control of the octopus cardiovascular system as neuropeptides and/or neurohormones.2.Octopus gonadtropin-reieasing hormone (GnRH)-like peptideA peptide with structural features similar to vertebrate GnRHs was isolated from brains of Octopus vulgaris. This peptide showed luteinizing hormone-releasing activity in quail anterior pituitary cells. The RT-PCR transcripts were expressed in the supraoesophageal and suboesophageal brains, peduncle complex, and optic gland. Immunoreactive neuronal cell bodies and fibers were observed in the subpedunculate lobe that controls the optic-gland activity. Optic gland nerves and glandular cells in the gland were immunostained. The isolated peptide may be Octopus GnRH that contributes to octopus reproduction not only as a neurohormone but also as an endocrine hormone.3.A second member of vasopressin/oxytocin (VP/OT)-superfamily peptides in OctopusOctocin was isolated as a second member of VP/UT-superfamily peptides in addition to the already known peptide, cephalotocin. The precursors of octocin and cephalotocin were highly similar to each other. The structural organizations were typical of the known VP/UT precursors : a signal sequence, a nonapeptide, and a neurophysin domain. The expressions of both peptides were different in the brain, namely, octocin was expressed mainly in the supraoesophageal lobes, which are concerned with voluntary movements, in contrast, and cephalotocin was expressed in the vasomotor lobes that send axons to the vena cava neurosecretory system.