Rendell M S, Milliken B K, Finnegan M F, Finney D A, Healy J C
Department of Medicine, Creighton University School of Medicine, Omaha, Nebraska 68131, USA.
Microvasc Res. 1997 May;53(3):222-34. doi: 10.1006/mvre.1997.2008.
Although vasodilation is conventionally held to be the predominant microvascular response to a wound, there has been no previous attempt to actually quantitate skin blood flow within and in the neighborhood of wounds. In particular, there has been no differentiation between sites with primarily nutritive (NUTR) blood flow and those with considerable arteriovenous (AV) perfusion. We used our previously described model of cutaneous blood flow in the rat to study the blood flow response to wounding. We measured skin blood flow at the centers and at the undisturbed perimeters of wounds placed at the back, a NUTR site, and at the paw, an AV site, in 11 Wistar Kyoto rats. Measurements were performed at baseline, and then at 3 hr, 24 hr, 72 hr, and 7 days postwounding. At 3 hr, flow at the center of the back wound had increased to 11.3 +/- 1.4 ml/min/100 g from a baseline of 2.1 +/- 0.1 ml/min/100 g and remained elevated at 7 days (8.3 ml/min/100 g). Flow at the perimeter of the back wound rose as well, but not as high as at wound center, to twice the baseline level (4.1 ml/min/ 100 g at Day 7). Flow values at control sites on the back did not increase from baseline. Flow at the center of the paw wound rose from 7.2 +/- 0.5 ml/min/100 g at baseline to 15.6 +/- 4.3 ml/min/100 g at Day 3 but then fell back to 6.9 +/- 0.9 ml/min/100 g at Day 7. There was only a very small increase in the basal temperature wound response at the paw perimeter. Blood flow at all wound sites showed a response to heat. At the back, heating to 44 degrees stimulated an 80% increase in blood flow at baseline. This degree of increase was maintained at both the center and the perimeter of the back wound. In contrast, although there was also a thermal response at the paw wound center, it was of much lower magnitude than the nonwounded baseline response. As a result, the heat-stimulated flow value actually fell over the 7 days to approximately half of the baseline level. At the paw wound periphery, there was an initial fall in the heat stimulated response, but it then recovered to the baseline level and remained stable over the 7 days. Thus, the skin blood flow response seen at the paw wound challenges the conventional concept of vasodilation as the expected wound blood flow response. The mechanisms of blood flow response in the healing wound may be more complex than the simple inflammatory vasodilation conventionally postulated.
虽然传统观点认为血管舒张是伤口主要的微血管反应，但此前尚无实际定量伤口内部及其周边皮肤血流的尝试。特别是，主要具有营养性（NUTR）血流的部位与具有大量动静脉（AV）灌注的部位之间没有区分。我们使用先前描述的大鼠皮肤血流模型来研究对伤口的血流反应。我们在11只Wistar Kyoto大鼠的背部（一个营养性部位）和爪子（一个动静脉部位）测量了伤口中心和未受干扰的周边的皮肤血流。在基线时进行测量，然后在受伤后3小时、24小时、72小时和7天进行测量。在3小时时，背部伤口中心的血流从基线的2.1±0.1毫升/分钟/100克增加到11.3±1.4毫升/分钟/100克，并在7天时保持升高（8.3毫升/分钟/100克）。背部伤口周边的血流也增加了，但不如伤口中心高，达到基线水平的两倍（第7天为4.1毫升/分钟/100克）。背部对照部位的血流值未从基线增加。爪子伤口中心的血流从基线的7.2±0.5毫升/分钟/100克在第3天增加到15.6±4.3毫升/分钟/100克，但在第7天又降至6.9±0.9毫升/分钟/100克。爪子周边伤口的基础温度反应仅略有增加。所有伤口部位的血流对热均有反应。在背部，加热至44摄氏度在基线时刺激血流增加80%。这种增加程度在背部伤口的中心和周边均保持。相比之下，虽然爪子伤口中心也有热反应，但其幅度远低于未受伤时的基线反应。结果，热刺激的血流值在7天内实际上降至基线水平的约一半。在爪子伤口周边，热刺激反应最初下降，但随后恢复到基线水平并在7天内保持稳定。因此，爪子伤口处观察到的皮肤血流反应挑战了血管舒张作为预期伤口血流反应的传统概念。愈合伤口中血流反应的机制可能比传统假设的简单炎症性血管舒张更为复杂。
