Mulvany M J, Hansen O K, Aalkjaer C
Circ Res. 1978 Dec;43(6):854-64. doi: 10.1161/01.res.43.6.854.
The mechanical and morphological properties of segments of certain precisely defined resistance vessels (approximately 150 micrometer lumen diameter) in the mesenteric bed of spontaneously hypertensive (SHR) and normotensive (WKY) rats have been compared in vitro under carefully controlled conditions and also after fixation. At a given transmural pressure, the relaxed SHR vessels (compared with the WKY vessels) would have had a 16% smaller lumen diameter (P less than 0.01) and a 49% thicker media (P less than 0.005), so that the media volume per unit segment length was 31% greater (P less than 0.05). The smooth muscle cells were arranged circumferentially in about four layers in the SHR vessels and in about three layers in the WKY vessels. The SHR active wall tension in response to potassium was 53% greater (P less than 0.02) and to norepinephrine was 50% greater (P less than 0.01) than for WKY. However, the ED50 values for the norepinephrine dose-response curves were similar (approximately 5 micrometer). Activation with potassium plus norepinephrine gave greater responses in both vessel types, than with either agent alone, but the SHR responses were on average only 19% greater than the WKY (P less than 0.10). However, under these conditions, the SHR vessels would have been able to contract against 45% greater transmural pressures (P less than 0.001) because of their smaller lumen. On maximal activation, the mean force developed by each cell (approximately 3.85 micro N) was the same in both vessel types, even though on average (P = 0.10) the SHR cells had a 21% greater cross-sectional area. The results support the Folkow hypothesis that in genetic hypertension the increased peripheral resistance is associated with structural changes in the resistance vessels.
在精心控制的体外条件下以及固定后，对自发性高血压大鼠（SHR）和正常血压大鼠（WKY）肠系膜床中某些精确界定的阻力血管段（管腔直径约150微米）的力学和形态学特性进行了比较。在给定的跨壁压力下，舒张状态的SHR血管（与WKY血管相比）管腔直径小16%（P<0.01），中膜厚49%（P<0.005），因此单位节段长度的中膜体积大31%（P<0.05）。SHR血管中的平滑肌细胞呈周向排列，约为四层，而WKY血管中约为三层。SHR血管对钾的主动壁张力比WKY血管高53%（P<0.02），对去甲肾上腺素的主动壁张力比WKY血管高50%（P<0.01）。然而，去甲肾上腺素剂量-反应曲线的ED50值相似（约5微米）。钾加去甲肾上腺素激活时，两种血管类型的反应均比单独使用任何一种药物时更大，但SHR血管的反应平均仅比WKY血管大19%（P<0.10）。然而，在这些条件下，由于SHR血管管腔较小，它们能够抵抗比WKY血管大45%的跨壁压力（P<0.001）。在最大激活时，尽管平均而言（P = 0.10）SHR细胞的横截面积大21%，但两种血管类型中每个细胞产生的平均力（约3.85微牛）相同。这些结果支持了福尔科夫假说，即在遗传性高血压中，外周阻力增加与阻力血管的结构变化有关。
