Kutsuzawa T, Yamabayashi H
Second Department of Internal Medicine, School of Medicine, Tokai University, Isehara.
Tohoku J Exp Med. 1988 Mar;154(3):305-14. doi: 10.1620/tjem.154.305.
Change in mixed venous oxygen tension (PVO2) during transition from rest to exercise induced by rhythmic contractions of the hindlimb of dogs was continuously monitored using intravascular oxygen electrodes. The rapid fall in PVO2, on the average 9.5 sec after the onset of rhythmic contraction, was found. The time course of change in PVO2 was not altered by ligation of the splenic artery and vein. Oxygen tension of venous blood in the superior vena cava and the inferior vena cava was monitored in order to elucidate the mechanism of rapid fall in PVO2 following induced exercise. Oxygen tension of venous blood in the superior vena cava did not fall at the onset of contraction. Oxygen tension of venous blood in the distal and proximal end of the inferior vena cava began to fall at 4.4 sec and at 6.9 sec after the onset of contraction on the average, respectively. There was no significant difference between the hematocrit of mixed venous blood at rest and after 15 sec of exercise. These findings suggest that the rapid fall of PVO2 results from a surge of low oxygenated blood from the exercising hindlimb and that this change in blood gas tensions possibly reaches the lung within 10 sec after the onset of exercise.
使用血管内氧电极连续监测狗后肢有节奏收缩诱导从休息到运动过程中混合静脉血氧分压（PVO2）的变化。发现PVO2在有节奏收缩开始后平均9.5秒迅速下降。脾动脉和静脉结扎未改变PVO2的变化时间进程。监测上腔静脉和下腔静脉中静脉血的氧分压，以阐明诱导运动后PVO2迅速下降的机制。收缩开始时上腔静脉中静脉血的氧分压未下降。下腔静脉远端和近端静脉血的氧分压分别在收缩开始后平均4.4秒和6.9秒开始下降。休息时和运动15秒后混合静脉血的血细胞比容无显著差异。这些发现表明，PVO2的迅速下降是由于来自运动后肢的低氧合血激增所致，并且这种血气张力变化可能在运动开始后10秒内到达肺部。
