Mahns D A, Courtice G P
School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
Regul Pept. 1996 Dec 17;67(3):163-8. doi: 10.1016/s0167-0115(96)00133-4.
Galanin is a neuropeptide that causes a marked pressor response in several non-mammalian vertebrate species, and some marsupials. In this study, the effect of three galanin antagonists were tested on the pressor response to an intravenous dose (6.3 nmol/kg) of porcine galanin in anaesthetised Cane toads, Bufo marinus. Antagonists were injected at either 20 or 50 times the molar dose (x MD) of galanin. The antagonist, C7 (Galanin 1-13-spantide) reduced the pressor effect of galanin by 32.2 +/- 6.0% when delivered at 20 x MD (n = 4) and by 42.9 +/- 15.7% when delivered at 50 x MD (n = 4) of galanin, the response recovering within 30 min. A second antagonist, M32a (Galanin 1-13-NPY 24-36) had no effect on the pressor response to galanin at 20 x MD (n = 4), but significantly reduced the pressor effect by 54.8 +/- 6.4% at 50 x MD (n = 5), which also recovered within 30 min. Administration of a third antagonist, galantide or M15 (Galanin 1-13-Substance P5-11), resulted in a profound drop in blood pressure, and did not affect the response to galanin at either dose. In conclusion, C7 and M32a are effective, short-term antagonists of the blood pressure effects of galanin in the toad.
甘丙肽是一种神经肽，在几种非哺乳类脊椎动物和一些有袋动物中会引起明显的升压反应。在本研究中，测试了三种甘丙肽拮抗剂对麻醉的海蟾蜍（Bufo marinus）静脉注射剂量（6.3 nmol/kg）猪甘丙肽引起的升压反应的影响。拮抗剂以甘丙肽摩尔剂量的20倍或50倍（x MD）注射。拮抗剂C7（甘丙肽1 - 13 - 肌氨酸）在以甘丙肽20 x MD给药时（n = 4）使甘丙肽的升压作用降低了32.2±6.0%，在以50 x MD给药时（n = 4）降低了42.9±15.7%，反应在30分钟内恢复。第二种拮抗剂M32a（甘丙肽1 - 13 - 神经肽Y 24 - 36）在20 x MD时（n = 4）对甘丙肽的升压反应没有影响，但在50 x MD时（n = 5）显著降低了升压作用，降低了54.8±6.4%，也在30分钟内恢复。第三种拮抗剂加兰他肽或M15（甘丙肽1 - 13 - P物质5 - 11）的给药导致血压大幅下降，且在两种剂量下均不影响对甘丙肽的反应。总之，C7和M32a是蟾蜍中甘丙肽血压效应的有效短期拮抗剂。
