Vovenko E P
Ross Fiziol Zh Im I M Sechenova. 2007 Jun;93(6):643-54.
Using polarographic oxygen microelectrodes, distribution of oxygen tension (pO2) in the rat cerebral arterioles (with a lumen diameter of 8-80 microm) and venules (with a lumen diameter of 8-120 microm) has been studied in acute reduction of haemoglobin concentration in the blood. Isovolumic haemodilution with 5 % albumin solution has been performed stepwise from 14 g/dl (control) to 10 g/dl (step 1), 7 g/dl (step 2) and to 4.6 g/dl (step 3). It was shown that step 1 of haemodilution led to no impairment of oxygen supply to the brain cortex. Step 2 resulted in moderate increase of pO2 in arterioles, whereas in venules oxygen tension fell down substantially (on the average, to 32 mm Hg). Step 3 resulted insignificant increase of pO2 in arterioles. A further fall of pO2 (to 27 mm Hg) in studied venules was recorded. The portion of venules with low pO2 grew to 31% (only 3 % in control). Microregions with a near-to-zero pO2 were recorded in some capillaries. This indicates presence of hypoxic zones in brain tissue. Hypoxic and anoxic microregions originate at this stage of anemia in locations with relatively low and/or impaired blood supply.
使用极谱氧微电极，研究了在急性降低血液中血红蛋白浓度的情况下，大鼠脑小动脉（管腔直径为8 - 80微米）和小静脉（管腔直径为8 - 120微米）中氧张力（pO₂）的分布。用5%白蛋白溶液进行等容血液稀释，从14 g/dl（对照）逐步降至10 g/dl（步骤1）、7 g/dl（步骤2）和4.6 g/dl（步骤3）。结果表明，血液稀释的步骤1未导致脑皮质的氧供应受损。步骤2导致小动脉中pO₂适度增加，而小静脉中的氧张力大幅下降（平均降至32 mmHg）。步骤3导致小动脉中pO₂显著增加。在所研究的小静脉中记录到pO₂进一步下降（至27 mmHg）。pO₂低的小静脉比例增至31%（对照中仅为3%）。在一些毛细血管中记录到pO₂接近零的微区。这表明脑组织中存在缺氧区。在贫血的这个阶段，缺氧和无氧微区出现在血液供应相对较低和/或受损的部位。
