Honig C R, Odoroff C L, Frierson J L
Am J Physiol. 1980 Jan;238(1):H31-42. doi: 10.1152/ajpheart.1980.238.1.H31.
Erythrocyte-containing capillaries were counted in dog gracilis muscles freeze-clamped at rest and after twitch contraction at 4/s. In each of 21 muscles, 6--8 blocks were examined at -70 degrees C without fixation or staining; 15 fields were counted per block. Frequency analysis of capillaries per field based on the negative binomial distribution indicated that capillary density at rest was controlled by arterioles. Active vasomotion of these arterioles was "switched off" within 5 s after onset of exercise. Capillary density was then determined passively by stochastic rheologic factors acting at the individual capillaries. Thus exercise changes the site and the mechanism of capillary control. Recruitment occurred first where capillary density was lowest, and was complete in 15 s; this greatly decreased the heterogeneity of capillary spacing. Mean capillary density increased 1.5- to 3-fold, whereas flow increased almost 7-fold. Calculated mean velocity and mean transit time of erythrocytes in capillaries were 1.1 mm/s and 920 ms at rest and 4.2 mm/s and 215 ms after 3 min of exercise.
对处于静息状态以及以4次/秒频率进行抽搐收缩后的犬股薄肌进行冷冻钳夹，然后计数含红细胞的毛细血管。在21块肌肉中，每块肌肉取6 - 8个样本于-70℃下进行检查，不进行固定或染色；每个样本计数15个视野。基于负二项分布对每个视野的毛细血管进行频率分析表明，静息状态下的毛细血管密度受小动脉控制。运动开始后5秒内，这些小动脉的主动血管运动就“停止”了。然后，毛细血管密度由作用于单个毛细血管的随机流变因素被动决定。因此，运动改变了毛细血管控制的部位和机制。募集首先发生在毛细血管密度最低的部位，15秒内完成；这大大降低了毛细血管间距的异质性。平均毛细血管密度增加了1.5至3倍，而血流量增加了近7倍。计算得出，静息状态下毛细血管中红细胞的平均速度和平均通过时间分别为1.1毫米/秒和920毫秒，运动3分钟后分别为4.2毫米/秒和215毫秒。
