Andriantsitohaina R, Stoclet J C, Bukoski R D
Laboratoire de Pharmacologie Cellulaire et Moléculaire, Universite Louis Pasteur de Strasbourg, Centre National de la Recherche Scientifique, Illkirch, France.
J Pharmacol Exp Ther. 1991 Apr;257(1):276-81.
The role of the endothelium in the effects of neuropeptide Y (NPY) and norepinephrine was investigated in mesenteric resistance arteries of the spontaneously hypertensive rat (SHR) and of the normotensive Wistar-Kyoto rat (WKY). Endothelium-dependent relaxation to acetylcholine (1 microM) was reduced in arteries of SHR compared with WKY. In the presence of the endothelium, the vessels of the two strains responded similarly to norepinephrine and NPY (100 nM) produced only a slight contraction. After removal of the endothelium, the response to norepinephrine was greater in WKY than in SHR. Furthermore, endothelium denudation enhanced markedly contraction elicited by NPY in WKY (up to 40% of the maximal effect of norepinephrine), but not in SHR. NPY potentiated the contractile response to low concentrations of norepinephrine (less than 300 nM) in both strains regardless whether the endothelium was intact or not. These results indicate that the contractile responses to NPY and to norepinephrine are inhibited by the endothelium in vessels of WKY, but not in those of the SHR. Furthermore, the potentiating effect of NPY occurs via an endothelium-independent mechanism in mesenteric arteries of both SHR and WKY. It is proposed that the differential responses between the two strains are related to abnormal function of the endothelium and to decreased responsiveness of smooth muscle cells in mesenteric resistance arteries of SHR compared to WKY.
在自发性高血压大鼠（SHR）和正常血压的Wistar-Kyoto大鼠（WKY）的肠系膜阻力动脉中，研究了内皮在神经肽Y（NPY）和去甲肾上腺素作用中的角色。与WKY相比，SHR动脉中对乙酰胆碱（1微摩尔）的内皮依赖性舒张作用减弱。在内皮存在的情况下，两种品系的血管对去甲肾上腺素的反应相似，而NPY（100纳摩尔）仅产生轻微收缩。去除内皮后，WKY对去甲肾上腺素的反应比SHR更强。此外，内皮剥脱显著增强了WKY中由NPY引起的收缩（高达去甲肾上腺素最大效应的40%），但在SHR中没有。无论内皮是否完整，NPY在两种品系中均增强了对低浓度去甲肾上腺素（小于300纳摩尔）的收缩反应。这些结果表明，WKY血管中内皮抑制了对NPY和去甲肾上腺素的收缩反应，但SHR血管中则没有。此外，NPY的增强作用在SHR和WKY的肠系膜动脉中均通过内皮非依赖机制发生。有人提出，两种品系之间的差异反应与内皮功能异常以及与WKY相比SHR肠系膜阻力动脉中平滑肌细胞反应性降低有关。
