Bowen J C, Garg D K
Gastroenterology. 1977 Jul;73(1):84-8.
Oxygen tension and potential difference were measured in the gastric mucosa of anesthetized dogs with an ultramicroelectrode technqiue while total blood flow and arteriovenous oxygen content difference were measured. In the control period, measurements were: gastric blood flow, 102.4 +/- 3.0 ml per min per 100 g of tissue; calculated oxygen consumption, 2.4 +/- 0.1 ml per min per 100 g of tissue; intracellular oxygen tension, 15.0 +/- 0.6 mm Hg; and intracellular potential difference, -50.8 +/- 1.5 mv. When gastric blood flow was reduced 50% by tourniquet ischemia, oxygen tension decreased 20% (P less than 0.05) but electrical potential and oxygen consumption did not change. When blood flow was reduced 75%, oxygen tension and potential difference decreased significantly, 60% and 35%, respectively, but oxygen consumption was unchanged. Zero blood flow reduced oxygen tension, electrical potential, and total oxygen consumption to zero; release of the arterial tourniquet allowed them to return to control levels. The critical oxygen tension at which the electromotive force generated by the gastric mucosal cells was reduced averaged 9 mm Hg. This suggests that safety factors exist in the gastric circulation which permit a 60% reduction in total gastric blood flow to occur before an insufficiency of intracellular oxygen begins to limit cellular metabolism within the mucosa.
用超微电极技术在麻醉犬的胃黏膜中测量氧分压和电位差，同时测量总血流量和动静脉氧含量差。在对照期，测量结果如下：胃血流量，每100克组织每分钟102.4±3.0毫升；计算得出的氧消耗量，每100克组织每分钟2.4±0.1毫升；细胞内氧分压，15.0±0.6毫米汞柱；细胞内电位差，-50.8±1.5毫伏。当用止血带缺血使胃血流量减少50%时，氧分压降低20%（P<0.05），但电位和氧消耗量未改变。当血流量减少75%时，氧分压和电位差分别显著降低60%和35%，但氧消耗量未变。零血流量使氧分压、电位和总氧消耗量降至零；松开动脉止血带可使其恢复到对照水平。胃黏膜细胞产生的电动势降低时的临界氧分压平均为9毫米汞柱。这表明胃循环中存在安全因素，在细胞内氧不足开始限制黏膜内细胞代谢之前，可使胃总血流量减少60%。
