Heterogeneities and profiles of oxygen pressure in brain and kidney as examples of the pO2 distribution in the living tissue

Hif-1

“…The best established method is using polarographic microelectrodes, but the spatial resolution is relatively low and the electrode disturbs and damages the tissue and also consumes oxygen (68). However, it is clear that within tissues, there is often great heterogeneity in pO 2 , and readings of 10 to 40 mmHg are common in normal tissues, with readings in malignant tumors generally being lower (69).…”

Hypoxia: The Force that Drives Chronic Kidney Disease

“…102 Paradoxically, however, oxygenation of the renal parenchyma is poor, with oxygen tensions in the renal cortex averaging 30 mm Hg and those in the renal medulla being below 10 mm Hg. 103,104 The reason for this dramatic contrast between oxygen supply and oxygenation is due both to the way the kidney is built and to the function it performs. With regard to kidney structure, arterial and venous pre-glomerular and post-glomerular vessels run strictly parallel and in close contact to one another over long distances.…”

Perspective in Chronic Kidney Disease: Targeting Hypoxia-Inducible Factor (HIF) as Potential Therapeutic Approach

“…In renal cortex as well as medulla, branches of the renal arteries and veins run stringently parallel and in close contact with each other over long distances which allows oxygen to diffuse from the arterial system into the venous system before entering the capillary bed, 3,4 thus subjecting oxygen to a countercurrent exchange comparable with urea, and this mechanism is particularly relevant in the renal medulla, where it leads to oxygen tensions below 10 mmHg. 2 However, preglomerular arteries of the renal cortex also undergo the countercurrent exchange of oxygen, where oxygen tensions are about 30 mmHg with marked variability. 2,4 Moreover, most tubular segments have a very limited capacity for anaerobic energy generation and are dependent on oxygen to maintain active transtubular reabsorption of solutes.…”

“…2 However, preglomerular arteries of the renal cortex also undergo the countercurrent exchange of oxygen, where oxygen tensions are about 30 mmHg with marked variability. 2,4 Moreover, most tubular segments have a very limited capacity for anaerobic energy generation and are dependent on oxygen to maintain active transtubular reabsorption of solutes. Thus, the combination of limited tissue oxygen supply and high oxygen demand may be considered as the main reason for the susceptibility of the kidney to acute ischemic injury.…”

“…1 Moreover, tissue oxygen tensions in the renal parenchyma are also lower than in most other organs. 2 The uniqueness of the architecture of the renal vasculature explains the discrepancy between high oxygen supply and low tissue oxygen tensions of the kidney. In renal cortex as well as medulla, branches of the renal arteries and veins run stringently parallel and in close contact with each other over long distances which allows oxygen to diffuse from the arterial system into the venous system before entering the capillary bed, 3,4 thus subjecting oxygen to a countercurrent exchange comparable with urea, and this mechanism is particularly relevant in the renal medulla, where it leads to oxygen tensions below 10 mmHg.…”