Damon Deborah H, Teriele Jaclyn A, Marko Stephen B
Department of Pharmacology, University of Vermont, 89 Beaumont Avenue, Burlington, VT 05405, USA.
Am J Physiol Heart Circ Physiol. 2007 Jul;293(1):H266-73. doi: 10.1152/ajpheart.00859.2006. Epub 2007 Mar 2.
Vascular sympathetic innervation is an important determinant of blood pressure and blood flow. The mechanisms that determine vascular sympathetic innervation are not well understood. The present study tests the hypothesis that vascular-derived artemin promotes the development of sympathetic innervation to blood vessels by promoting sympathetic axon growth. RT-PCR and Western analyses indicate that artemin is expressed by cultured vascular smooth muscle and arteries, and artemin coreceptors, glial cell-derived neurotrophic factor family receptor alpha3 and ret, are expressed by postganglionic sympathetic neurons. The effects of artemin on axon growth were assessed on explants of neonatal rat sympathetic ganglia. In the presence, but not in the absence, of nerve growth factor, exogenous artemin stimulated neurite growth. Femoral arteries (FA) from adult rats contain artemin, and these arteries stimulated sympathetic neurite growth. Growth in the presence of FA was 92.2 +/- 11.9 mm, and that in the absence of FA was 26.3 +/- 5.4 mm (P < 0.05). FA stimulation of axon growth was reduced by an antibody that neutralized the activity of artemin (P < 0.05). These data indicate that artemin is expressed in arteries, and its receptors are expressed and functional in the postganglionic sympathetic neurons that innervate them. This suggests that artemin may be a determinant of vascular sympathetic innervation.
血管交感神经支配是血压和血流的重要决定因素。决定血管交感神经支配的机制尚未完全明确。本研究检验了一种假说，即血管源性的artemin通过促进交感神经轴突生长来促进血管交感神经支配的发育。逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹分析表明，artemin在培养的血管平滑肌和动脉中表达，而artemin共受体、胶质细胞源性神经营养因子家族受体α3和ret在节后交感神经元中表达。通过新生大鼠交感神经节外植体评估了artemin对轴突生长的影响。在有神经生长因子存在而非不存在的情况下，外源性artemin刺激了神经突生长。成年大鼠的股动脉（FA）含有artemin，并且这些动脉刺激了交感神经突生长。有FA存在时的生长长度为92.2±11.9毫米，无FA时为26.3±5.4毫米（P<0.05）。一种中和artemin活性的抗体降低了FA对轴突生长的刺激作用（P<0.05）。这些数据表明，artemin在动脉中表达，其受体在支配动脉的节后交感神经元中表达且具有功能。这表明artemin可能是血管交感神经支配的一个决定因素。
