Pollock F E, Smith T L, Koman L A
Department of Orthopaedic Surgery, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC.
Microsurgery. 1994;15(6):433-8. doi: 10.1002/micr.1920150613.
Conditions such as Raynaud's disease, cold intolerance following digit replantation, and reflex sympathetic dystrophy are all exacerbated by diminished blood flow in the digits. The rabbit ear, being similar to the human digit, is an excellent model for studying microvascular responses during thermoregulation and was used in this study of microcirculatory changes during total-body cold stress. In eight rabbits a window was placed in one ear each, and the underlying vascular beds were photographed with the unanesthetized animal at room temperature (23 degrees C) and in a cold room (6 degrees C). Luminal arterial diameters constricted more than venular diameters during cold stress (39.6% vs. 16.5%, respectively, of the control diameters; P = 0.014). All responses were linear; the slopes of the regression lines were significantly different between arterioles and venules (P < 0.0001). This study suggests that decreased circulation in response to cold is due to decreases in the diameter and number of vessels available for perfusion, as predicted by the Poiseuille equation.
诸如雷诺氏病、断指再植后对寒冷不耐受以及反射性交感神经营养不良等病症，都会因手指血流量减少而加重。兔耳与人的手指相似，是研究体温调节过程中微血管反应的绝佳模型，本研究利用兔耳来研究全身冷应激期间的微循环变化。在八只兔子身上，分别在每只耳朵上开一个窗口，在室温（23摄氏度）和冷室（6摄氏度）中对未麻醉动物的皮下血管床进行拍照。冷应激期间，管腔动脉直径比静脉直径收缩得更明显（分别为对照直径的39.6%和16.5%；P = 0.014）。所有反应均呈线性；小动脉和小静脉的回归线斜率有显著差异（P < 0.0001）。本研究表明，如泊肃叶方程所预测的那样，对寒冷的反应导致循环减少是由于可供灌注的血管直径和数量减少所致。
