Hongo K, Nakagomi T, Kassell N F, Sasaki T, Lehman M, Vollmer D G, Tsukahara T, Ogawa H, Torner J
Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville 22908.
Stroke. 1988 Jul;19(7):892-7. doi: 10.1161/01.str.19.7.892.
We evaluated the effects of aging and hypertension on endothelium-dependent relaxation of rat common carotid arteries using 14-week-old (young) and 11-month-old (old) Wistar-Kyoto rats (WKY) and age-matched spontaneously hypertensive rats (SHR). Isometric tension of common carotid artery ring segments was measured. With a resting tension of 2.0 g determined from the baseline tension-contraction curves, precontraction was induced by 10(-5) M 5-hydroxytryptamine and endothelium-dependent relaxation was measured by application of either acetylcholine or adenosine 5'-triphosphate (ATP). Mean arterial blood pressure was 73.1 +/- 3.0 mm Hg in WKY and 110.0 +/- 3.1 mm Hg in SHR. These baseline values were significantly different. Acetylcholine-induced maximal relaxations were 70.1 +/- 2.6% of the 5-hydroxytryptamine-induced contraction in young WKY, 45.6 +/- 2.1% in old WKY, 35.1 +/- 1.8% in young SHR, and 21.4 +/- 2.5% in old SHR. On the other hand, ATP-induced relaxations were 52.0 +/- 3.2%, 35.7 +/- 3.8%, 21.7 +/- 3.5%, and 17.0 +/- 1.8% in the groups, respectively. Acetylcholine-induced relaxations were significantly different between WKY and SHR, young and old, independently. On the other hand, ATP-induced relaxations were also significantly different between young and old WKY, although no significant difference was observed between young and old SHR. The fact that endothelium-dependent relaxation of a cephalic artery is impaired in old rats and in hypertensive rats suggests that aging and hypertension are risk factors that may augment the disturbance of the cerebral circulation in pathologic conditions.
我们使用14周龄（年轻）和11月龄（年老）的Wistar-Kyoto大鼠（WKY）以及年龄匹配的自发性高血压大鼠（SHR），评估了衰老和高血压对大鼠颈总动脉内皮依赖性舒张的影响。测量了颈总动脉环段的等长张力。根据基线张力-收缩曲线确定静息张力为2.0 g，用10(-5) M 5-羟色胺诱导预收缩，并通过应用乙酰胆碱或5'-三磷酸腺苷（ATP）测量内皮依赖性舒张。WKY的平均动脉血压为73.1±3.0 mmHg，SHR为110.0±3.1 mmHg。这些基线值有显著差异。乙酰胆碱诱导的最大舒张在年轻WKY中为5-羟色胺诱导收缩的70.1±2.6%，年老WKY中为45.6±2.1%，年轻SHR中为35.1±1.8%，年老SHR中为21.4±2.5%。另一方面，ATP诱导的舒张在各组中分别为52.0±3.2%、35.7±3.8%、21.7±3.5%和17.0±1.8%。乙酰胆碱诱导的舒张在WKY和SHR之间、年轻和年老之间均有显著差异。另一方面，ATP诱导的舒张在年轻和年老WKY之间也有显著差异，尽管在年轻和年老SHR之间未观察到显著差异。老年大鼠和高血压大鼠头动脉的内皮依赖性舒张受损这一事实表明，衰老和高血压是可能在病理状态下加剧脑循环紊乱的危险因素。
