| Abstract: | The influence of elevated pO₂ on regional blood flow of muscle tissue was studied using the hydrogen electrode technique, modified from that introduced by Aukland, Bower, and Berliner (1963). Baseline studies were conducted at 1 ATA. Six mongrel dogs serving as their own control were anesthetized, and their blood flow measured while breathing air, and while breathing 100% oxygen (pO₂ = 760 mmHg). It was determined that there was no significant difference between the blood flow rates in 31 experiments with these dogs subjected to the same experimental conditions. Also, it was determined that after 20 minutes of exposure to 100% O₂, the average blood flow rate in the muscle had decreased by 46.66%. Another group of dogs were placed in a hyperbaric chamber and compressed to 3 ATA. After 5, 10, 15, and 25 minutes of hyperbaric oxygen, it was found that the blood rate decreased with respect to time in an exponential manner following the expression: [line break] y = 15.00 e[superscript -0.04t] + 0.006 [line break] Where: y is in ml/min/100 gr of tissue [line break] Finally, a study was made to determine if more frequent periodic returns to air breathing would significantly increase blood flow, thereby increasing the oxygen available to the tissues. It was found that while muscle blood flow did, indeed, increase approximately 8.9% during 5 minutes of air breathing, the much greater reduction in pO₂ during air breathing more than off-set the benefits derived from the temporarily increased blood flow. |
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