Bosman J, Tangelder G J, Oude Egbrink M G, Reneman R S, Slaaf D W
Department of Biophysics, Cardiovascular Research Institute Maastricht, University of Limburg, The Netherlands.
Am J Physiol. 1995 Sep;269(3 Pt 2):H1048-55. doi: 10.1152/ajpheart.1995.269.3.H1048.
Capillary diameter changes were studied in the tenuissimus muscle of 29 urethan-anesthetized New Zealand White rabbits. Capillaries were visualized with transillumination bright-field microscopy (saltwater lens, x 50; resolution approximately 0.3 microns). Median capillary diameter during the control period was 4.4 microns (range 3.2-6.9 microns). Complete aortic occlusion resulted in a reduction of median femoral arterial pressure to 17 mmHg (range 4-22 mmHg). During 2 min of occlusion, capillary diameter decreased by 6%, with greater change on the arteriolar side of the capillary than on the venular side. During reactive hyperemia after release of the occluder, capillary diameter maximally increased by 12% compared with the control period, with a larger response at the arteriolar end of the capillary than at the venular end. Median capillary resistance was estimated to increase by 27% during occlusion and to decrease by 36% during peak reactive hyperemia. The observed diameter changes are compatible with the idea that capillaries change their diameter relative to changes in transmural pressure.
在29只经乌拉坦麻醉的新西兰白兔的薄肌中研究了毛细血管直径的变化。通过透照明场显微镜（盐水透镜，×50；分辨率约0.3微米）观察毛细血管。对照期的毛细血管直径中位数为4.4微米（范围3.2 - 6.9微米）。完全性主动脉闭塞导致股动脉压中位数降至17 mmHg（范围4 - 22 mmHg）。在闭塞2分钟期间，毛细血管直径减小了6%，毛细血管小动脉侧的变化大于小静脉侧。在松开闭塞器后的反应性充血期间，与对照期相比，毛细血管直径最大增加了12%，毛细血管小动脉端的反应大于小静脉端。估计毛细血管阻力中位数在闭塞期间增加27%，在反应性充血峰值期间降低36%。观察到的直径变化与毛细血管直径随跨壁压力变化而改变的观点相符。
