Preston E, McManus C D, Jonsson A C, Courtice G P
School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
Regul Pept. 1995 Aug 22;58(3):123-34. doi: 10.1016/0167-0115(95)00060-o.
Galanin is found in perivascular sympathetic neurons in a wide range of vertebrate species. In placental mammals, galanin has either no effect on blood pressure, or weak depressor effects, but in other vertebrates it has been shown to be a potent pressor agent. To investigate how extensive the vasoconstrictor effects of galanin may be in the vertebrates, the vascular effects of galanin were tested in two species of shark, Heterodontus portusjacksoni, and Hemiscyllium ocellatum, and a ray, Rhinobatos typus. Nerve fibres showing immunoreactivity to galanin were located surrounding gut blood vessels, but were absent from branchial efferent arteries in all three species. Intravenous injection of galanin caused a significant rise in caudal arterial blood pressure in H. portusjacksoni and H. ocellatum, but no change in R. typus. Contraction of segments of pancreatico-mesenteric artery were measured in an organ bath also. Galanin (10(-6) M) caused 21-38% of the maximum K+ induced contraction in all species, but no response in efferent branchial arteries from R. typus. In conclusion, in three elasmobranchs, a galanin-like peptide is present in perivascular nerve fibres, and galanin causes differential vasoconstriction in vascular beds. These data extend the number of vertebrate groups in which galanin has been shown to be a vasoconstrictor peptide.
甘丙肽存在于多种脊椎动物物种的血管周围交感神经元中。在胎盘哺乳动物中，甘丙肽对血压要么没有影响，要么有微弱的降压作用，但在其他脊椎动物中，它已被证明是一种强效的升压剂。为了研究甘丙肽的血管收缩作用在脊椎动物中的广泛程度，在两种鲨鱼（杰克逊港异齿鲨和眼斑半环鲨）以及一种鳐鱼（蒂普斯鼻鳐）中测试了甘丙肽的血管效应。显示对甘丙肽有免疫反应性的神经纤维位于肠道血管周围，但在所有这三个物种的鳃传出动脉中均不存在。静脉注射甘丙肽导致杰克逊港异齿鲨和眼斑半环鲨的尾动脉血压显著升高，但蒂普斯鼻鳐没有变化。还在器官浴中测量了胰肠系膜动脉段的收缩情况。甘丙肽（10⁻⁶ M）在所有物种中引起了最大钾离子诱导收缩的21% - 38%，但蒂普斯鼻鳐的鳃传出动脉没有反应。总之，在三种板鳃亚纲动物中，血管周围神经纤维中存在一种甘丙肽样肽，并且甘丙肽在血管床中引起不同的血管收缩。这些数据扩展了已证明甘丙肽是血管收缩肽的脊椎动物类群数量。
