Increased brain capillaries in chronic hypoxia
Increased brain capillaries in chronic hypoxia
复制标题
DOI：
10.1152/jappl.1999.86.4.1211
复制
发表时间：
1999-04-01
影响因子：
3.3
通讯作者：
Woolsey, TA
中科院分区：
文献类型：
--
作者：
Boero, JA;Ascher, J;Woolsey, TA
本文研究了慢性低压低氧(28天，455Torr)对Balb/c小鼠脑血管组织的影响。与保持在海平面的年龄匹配的对照组相比，低氧小鼠的乳剂灌流的毛细血管在所有研究的大脑区域都显示出显著的扩张。单位体积的毛细血管长度在小脑颗粒层、尾状核、苍白球、黑质、上丘和齿状回增加。在海马(CA_1层、锥体和腔隙、CA_3层、锥体和东方)，在体感皮质V、VI层，运动皮质II、III、V、VI层，以及听皮质II、III、V、VI层，FT有选择性地增加。单位体积组织的毛细血管表面积在几个脑区也有增加，包括躯体感觉皮质IV层，L-v的增加不明显。用数学模型估算组织中氧扩散电导和氧分压。慢性缺氧时毛细血管内径和长度的重塑是导致神经组织氧传导性显著增加的原因。此外，与急性缺氧相比，慢性脑缺氧时尾状核和黑质中估计的组织POT显着增加。这些结果表明，新生毛细血管的形成是恢复慢性脑缺氧时氧缺乏的重要机制，局部能量利用率可能影响大脑不同区域的血管生成。
The effect of chronic hypobaric hypoxia (28 days, 455 Torr) on the organization of brain vessels was studied in Balb/c mice. In comparison to age-matched controls kept at sea level, emulsion-perfused capillaries in hypoxic mice showed marked dilation in all brain areas studied. Capillary length per unit volume of tissue (L-v) was increased in the cerebellar granular layer, the caudate nucleus, the globus pallidus, the substantia nigra, the superior colliculus, and the dentate gyrus. There was a selective increase oft, in the hippocampus (CA1 strata pyramidale and lacunosum and CA3 strata pyramidale and oriens) and in somatosensory cortex layers V and VI, motor cortex layers II, III, V, and VI, and auditory cortex layers II and III. An increase in capillary surface area per unit volume of tissue was also determined in several brain areas, including layer IV of somatosensory cortex, where L-v was not significantly increased. The O-2 diffusion conductance and PO2 in the tissues were estimated with a mathematical model. The remodeling of capillary diameter and length during chronic hypoxia accounts for the significant increase of O-2 conductance to neural tissues. Also the estimated tissue Pot in chronic brain hypoxia is markedly increased in the caudate nucleus and the substantia nigra compared with acute hypoxia. These results suggest that formation of new capillaries is an important mechanism to restore the O-2 deficit in chronic brain hypoxia and that local rates of energy utilization may influence angiogenesis in different areas of the brain.