【摘要】 采用２月龄、１４月龄和１８月龄三个不同年龄阶段的大鼠，在离体灌流的阻力血管组织—肠系膜动脉床和离体温育的脊髓切片上，观察了降钙素基因相关肽（ＣＧＲＰ）在感觉神经外周端和中枢端释放的老年性改变。发现１８月龄的大鼠基础释放及辣椒素刺激后的释放均较２月龄大鼠显著为低；又用免疫组织化学方法对比观察了不同年龄大鼠血管组织中ＣＧＲＰ的分布，发现１４月龄大鼠阻力血管组织中ＣＧＲＰ能神经分布减少；进一步用半定量ＲＴ－ＰＣＲ方法观察到老年大鼠ＣＧＲＰ在合成部位—脊髓背根神经节的ｍＲＮＡ水平增高。证实ＣＧＲＰ组织含量和释放的老年性降低并不是发生于ＣＧＲＰ转录环节。我们推测ＣＧＲＰ的这种改变与老年时血管张力调节失衡，血管阻力增高有关，可能是老年时高血压等心血管疾患发病率增高的机制之一。更多还原

【Abstract】 The age related changes of calcitonin gene related peptide (CGRP) were studied in 2, 14 and 18 month old Wistar rats. The release of CGRP from peripheral and central endings of sensory nerves was investigated in isolated perfused mesenteric arterial beds and incubated spinal cord slices. The basal and stimulated (by capsaicin, 10 -7 ——3×10 -6 mol/L for arterial beds, and 10 -7 ——10 -6 mol/L for spinal cord) CGRP release in both tissues were decreased significantly in 14 and 18 month old rats. Immunohistochemistry study showed an attenuation of CGRP content and innervation in peripheral vasculature of aged rats. By using semi quantitative RT PCR, it was found that a 29% elevation of CGRP mRNA level in spinal dorsal root ganglions, where CGRP was synthesized, in 18 month old rats compared with 2 month ones, suggesting that age related changes of CGRP may occur at some stages other than mRNA level. The data suggest that the age related changes of CGRP may induce the functional impairment of peripheral vasodilation and nervous system which may play an important role in pathogenesis of aging related disease, especially in vascular disorders such as hypertension.更多还原