Phillips J K, Vidovic M, Hill C E
Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australia.
Mech Ageing Dev. 1996 Dec 20;92(2-3):235-46. doi: 10.1016/s0047-6374(96)01841-6.
Developmental studies show that the innervation of autonomic targets is accompanied by increases in the density of receptors, maturation of receptor-signalling pathways and changes in receptor subtype. The innervation of the rat mesenteric artery occurs over the first 3 postnatal weeks. In this study, we investigated whether alterations in receptor gene expression may underlie physiological changes recorded during development and maturity in this vessel. Total RNA, from mesenteric arteries of rats at birth and postnatal days 7, 14, 28, 240 and 360, was reverse transcribed and amplified using primers specific for the alpha 1 (A, B, D)- and alpha 2 (A, B, C)-adrenergic, neurokinin (NK1-NK3) and muscarinic (m1-m5) receptors. Results showed that all receptor genes expressed at 28 days, except the alpha 1D-adrenergic receptor, were already expressed at birth. Some receptor subtypes showed no change in their relative expression, always being either strongly (alpha 1A, alpha 2B, NK3) or weakly (alpha 2A, alpha 2C, NK1) expressed. Relative to the expression of these receptors, others showed a developmental increase in expression up to 14 days postnatal (alpha 1B, alpha 1D, m2, m3, m5) but no further change with maturity. These latter changes coincide with the development of sympathetic and sensory nerve plexuses in the mesenteric artery, but do not correlate with the physiological changes seen during development and ageing.
发育研究表明，自主神经靶器官的神经支配伴随着受体密度的增加、受体信号通路的成熟以及受体亚型的变化。大鼠肠系膜动脉的神经支配在出生后的前三周内发生。在本研究中，我们调查了受体基因表达的改变是否可能是该血管在发育和成熟过程中所记录的生理变化的基础。使用针对α1（A、B、D）-和α2（A、B、C）-肾上腺素能、神经激肽（NK1-NK3）和毒蕈碱（m1-m5）受体的特异性引物，对出生时、出生后第7天、14天、28天、240天和360天大鼠肠系膜动脉的总RNA进行逆转录和扩增。结果显示，除α1D-肾上腺素能受体外，所有在28天时表达的受体基因在出生时就已表达。一些受体亚型的相对表达没有变化，始终要么强烈表达（α1A、α2B、NK3），要么弱表达（α2A、α2C、NK1）。相对于这些受体的表达，其他受体在出生后14天内表达呈发育性增加（α1B、α1D、m2、m3、m5），但成熟后没有进一步变化。后一种变化与肠系膜动脉中交感和感觉神经丛的发育一致，但与发育和衰老过程中观察到的生理变化无关。
