Juarbe C, Sillau A H
Department of Physiology and Biophysics, School of Medicine, University of Puerto Rico, San Juan 00936.
Respir Physiol. 1988 Apr;72(1):83-94. doi: 10.1016/0034-5687(88)90081-3.
To investigate the effects of low P50Hb on muscle capillarity, rats were injected with Na-cyanate (50 mg/kg BW) every day for 2 or 4 weeks (experimental). Controls received injections of saline. After 2 weeks P50 was reduced in the experimental animals (20.4 vs 30.3 Torr). After 4 weeks experimental animals showed a 13% increase in hematocrit and Hb. PVO2 was lower in experimental than in control rats (28.3 +/- 1.0 vs 33.8 +/- 4.7 mm Hg). Fiber cross-sectional area (FCSA), capillary density (CD) and capillary-to-fiber ratio (C/F) were measured in sections treated with the ATPase technique. FCSA was smaller in experimental than in controls (3000 +/- 491 vs 4121 +/- 415 micron 2 for the soleus and 3633 +/- 236 vs 4251 +/- 194 micron 2 for the gastrocnemius) and CD was higher (729 +/- 99 vs 578 +/- 75 cap/mm2 in the soleus and 388 +/- 19 vs 323 +/- 14 cap/mm2 in the gastrocnemius) but C/F was not different. Diffusion distances for O2 measured by the closest individual method were not significantly different between the two groups. The higher CD in the experimental animals seems to be the result of their smaller FCSA and not the result of capillary proliferation. The volume of tissue served by a capillary was significantly reduced in the experimental animals. This could help the transfer of O2 to the muscle in animals with a low P50 Hb.
为研究低P50血红蛋白对肌肉毛细血管的影响，将大鼠每天注射氰酸钠（50毫克/千克体重），持续2周或4周（实验组）。对照组注射生理盐水。2周后，实验组动物的P50降低（20.4对30.3托）。4周后，实验组动物的血细胞比容和血红蛋白增加了13%。实验组大鼠的混合静脉血氧分压低于对照组（28.3±1.0对33.8±4.7毫米汞柱）。采用ATP酶技术处理切片，测量纤维横截面积（FCSA）、毛细血管密度（CD）和毛细血管与纤维比率（C/F）。实验组的FCSA小于对照组（比目鱼肌为3000±491对4121±415平方微米，腓肠肌为3633±236对4251±194平方微米），而CD较高（比目鱼肌为729±99对578±75根/平方毫米，腓肠肌为388±19对323±14根/平方毫米），但C/F无差异。通过最近个体法测量的两组之间氧气扩散距离无显著差异。实验组动物较高的CD似乎是其较小的FCSA的结果，而非毛细血管增殖的结果。实验组动物中由一根毛细血管供应的组织体积显著减少。这可能有助于低P50血红蛋白动物的氧气向肌肉的转运。
