Rendell M S, Milliken B K, Banset E J, Finnegan M, Stanosheck C, Terando J V
Creighton Diabetes Center, Omaha, NE 68131, USA.
J Hypertens. 1996 May;14(5):609-14. doi: 10.1097/00004872-199605000-00010.
To determine whether the cutaneous microvasculature of the spontaneously hypertensive rat (SHR) is affected by chronic hypertension.
We used laser Doppler techniques to measure skin blood flow in 22 SHR and in 22 non-hypertensive Wistar-Kyoto (WKY) rats over a 1-year time span, beginning at age 3 months. Sites of measurement included the back, leg, and root of the tail, areas with a predominantly nutritive perfusion, and the plantar surface of the paw, which has a large contribution from large arterioles and venules. Flow was measured at basal skin temperature and at the maximally heat-stimulated condition of 44 degrees C. Systolic tail arterial blood pressures were measured concurrently.
At baseline, systolic blood pressures were considerably higher in the SHR (190 +/- 4 mmHg) than they were in the WKY rats (138 +/- 2 mmHg). Skin blood flow values at the three nutritive sites were similar in the two species. However, at 44 degrees C, flow was significantly higher at the paw in the SHR (46.8 +/- 3.5 versus 34.3 +/- 2.2 ml/min per 100 g). We attribute this difference to the effect of high perfusion pressure on large arterioles. During the 1-year measurement period, there was no appreciable change in blood flow in the WKY rats. In contrast, the SHR showed a steady progressive decline in skin blood flow at all sites. The largest decline was at the paw with a rate of fall of about 2.4%/month. After 1 year, there was no difference between paw blood flow in the SHR (27.5 +/- 1.8 ml/min per 100 g) and in the WKY rats (27.6 +/- 1.9 ml/min per 100 g).
Skin blood flow reserve falls in response to chronic hypertension. The rate of fall is greater at sites with significant arteriovenous perfusion that at nutritive sites.
确定自发性高血压大鼠（SHR）的皮肤微血管系统是否受慢性高血压影响。
我们使用激光多普勒技术，在1年时间跨度内，对22只SHR和22只非高血压Wistar - Kyoto（WKY）大鼠从3月龄开始测量皮肤血流。测量部位包括背部、腿部和尾根部，这些区域主要是营养性灌注区域，以及爪的足底表面，该部位有大量大的小动脉和小静脉供血。在基础皮肤温度和44℃最大热刺激条件下测量血流。同时测量收缩期尾动脉血压。
基线时，SHR的收缩压（190±4 mmHg）显著高于WKY大鼠（138±2 mmHg）。两个物种在三个营养性部位的皮肤血流值相似。然而，在44℃时，SHR爪部的血流显著更高（46.8±3.5对34.3±2.2 ml/min per 100 g）。我们将这种差异归因于高灌注压力对大的小动脉的影响。在1年的测量期内，WKY大鼠的血流没有明显变化。相比之下，SHR在所有部位的皮肤血流均呈稳定的逐渐下降。下降最大的是爪部，下降速率约为每月2.4%。1年后，SHR爪部的血流（27.5±1.8 ml/min per 100 g）与WKY大鼠（27.6±1.9 ml/min per 100 g）之间没有差异。
皮肤血流储备因慢性高血压而下降。在动静脉灌注显著的部位，下降速率比营养性部位更大。
