Characteristics and origin of myogenic response in isolated gracilis muscle arterioles.
Characteristics and origin of myogenic response in isolated gracilis muscle arterioles.
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离体股薄肌小动脉生肌反应的特征和起源。
DOI：
10.1152/ajpheart.1994.266.3.h1177
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Koller,A
中科院分区：
文献类型：
--
作者：
Sun,D;Kaley,G;Koller,A
在无血流状态下，观察大鼠股薄肌肌小动脉对血管内压变化的反应。分离并插管一、二、三级小动脉。用图像剪切仪测量血管直径并记录。随着灌流压力的阶跃升高(从20至160毫米汞柱，递增10或20毫米汞柱)，小动脉收缩并形成主动张力。例如，在100、80和50毫米汞柱压力下，一、二、三级小动脉的稳态活动直径分别为76.9±1.6微米、32.3±1.1微米和22.3±3.2微米。在相同的灌流压力下，用含硝普钠的无钙溶液(乙二醇双(β-氨基乙醚)-N，N，N‘，N’-四乙酸乙酯；1 mm)，这些血管的被动直径(PD)分别为161.8+/-3.2，76.0+/-1.7，47.6+/-2.2微米。压力-直径曲线的负斜率表明，在生理压力范围内，小动脉直径与血管内压之间存在负相关关系。以PD百分比表示的最大收缩在不同大小的小动脉中相似(约60%)，但在较小的血管中在较低的压力下达到。以空气去除内皮前后小动脉对乙酰胆碱(ACh；10(-6)M)和硝普钠(SNP，5×10(-8)M)的反应性来评价内皮和血管平滑肌的血管活性。去除内皮细胞后，对ACh的扩张被取消，而对SNP的扩张被保留。
Responses to changes in intravascular pressure of isolated rat gracilis muscle arterioles were investigated under no-flow conditions. First-, second-, and third- order arterioles were isolated and cannulated. Vascular diameters were measured with an image-shearing device and then recorded. In response to the step increases in perfusion pressure (from 20 to 160 mmHg, by 10- or 20-mmHg steps) arterioles constricted and developed active tone. For example, at 100, 80, and 50 mmHg pressure the steady-state active diameters of 1st-, 2nd-, and 3rd-order arterioles were 76.9 +/- 1.6, 32.3 +/- 1.1 and 22.3 +/- 3.2 microns, respectively. At the same perfusion pressure, by use of a Ca(2+)-free solution (ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid; 1 mM) containing sodium nitroprusside (SNP; 10(-4) M), the passive diameters (PD) of these vessels were 161.8 +/- 3.2, 76.0 +/- 1.7, and 47.6 +/- 2.2 microns. The negative slopes of the pressure-diameter curves indicate that in the physiological pressure range an inverse relationship exists between the arteriolar diameter and intravascular pressure. The maximum constriction expressed as a percent of PD was similar in the various sized arterioles (approximately 60%) but was reached at lower pressures in the smaller vessels. The vasoactive function of endothelium and vascular smooth muscle was assessed by the responses of arterioles to acetylcholine (ACh; 10(-6) M) and SNP (5 x 10(-8) M) before and after removal of the endothelium with air. After removal of the endothelium, dilation to ACh was abolished while dilation to SNP was retained.(ABSTRACT TRUNCATED AT 250 WORDS)