Tissue damage, concentration-related

It should be noted that initially the urea and creatinine may be normal in ARF. The serum potassium usually rises very quickly in catabolic patients, with or without tissue damage, and falls quickly once the urine flow rate increases. The urine volume cannot be related to the GFR. The serum urea and ereatininc remain high during the diuretic phase, because the GFR is still low and the large urine volumes rcllect tubular damage. In the recovery phase the serum urea and creatinine fall as the GFR improves and the. serum potassium concentration returns to normal, as the tubular mechanisms recover. 

At a macroscopic biological level, the damage to tissue is related to the concentration of photosensitizer and dioxygen in the tissues being irradiated, and to the light flux the key mechanistic questions here are—in which compartment does the photosensitizer accumulate,... 

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