DiPette D J, Schwarzenberger K, Kerr N, Holland O B
Department of Medicine, University of Texas Medical Branch, Galveston 77550.
Am J Med Sci. 1989 Feb;297(2):65-70. doi: 10.1097/00000441-198902000-00001.
The dose-response effects of infused calcitonin gene-related peptide (CGRP), a potent vasodilator, on systemic and regional hemodynamics in the conscious rat remain incompletely defined. The radioactive microsphere technique provided these determinations before and after the intravenous administration of vehicle or 22, 65, 220, and 2200 pmol of CGRP. Neither vehicle nor 22 pmol of CGRP significantly changed any systemic or regional hemodynamic parameter. Starting at the 65-pmol dose, CGRP significantly decreased mean blood pressure and total peripheral resistance, while increasing heart rate without changing cardiac output. CGRP produced selective regional vasodilatory effects, with the coronary circulation being unusually sensitive. In contrast, CGRP caused significant increases in blood flow to the mesenteric and cutaneous circulations only at the two highest doses. CGRP increased plasma norepinephrine, epinephrine, and renin activity significantly at only the 2200-pmol dose. In conclusion, CGRP decreases blood pressure by peripheral vasodilation, with a threshold dose occurring between 22 and 65 pmol. In addition, the coronary circulation appears to be particularly sensitive to the vasodilatory properties of CGRP.
强效血管扩张剂降钙素基因相关肽（CGRP）对清醒大鼠全身和局部血流动力学的剂量反应效应尚未完全明确。放射性微球技术在静脉注射赋形剂或22、65、220和2200皮摩尔CGRP之前和之后进行了这些测定。赋形剂和22皮摩尔CGRP均未显著改变任何全身或局部血流动力学参数。从65皮摩尔剂量开始，CGRP显著降低平均血压和总外周阻力，同时增加心率而不改变心输出量。CGRP产生选择性局部血管扩张作用，冠状动脉循环异常敏感。相比之下，CGRP仅在两个最高剂量时才会导致肠系膜和皮肤循环的血流量显著增加。CGRP仅在2200皮摩尔剂量时才会显著增加血浆去甲肾上腺素、肾上腺素和肾素活性。总之，CGRP通过外周血管扩张降低血压，阈值剂量在22至65皮摩尔之间。此外，冠状动脉循环似乎对CGRP的血管扩张特性特别敏感。
