Pulmonary and cutaneous oxygen uptake and oxygen consumption of isolated skin in the frog, Rana pipiens.

Oxygen uptake and consumption rates were measured in intact and isolated skin from the amphibian Rana pipiens to determine the percentage of total cutaneous O2 uptake that is consumed by the skin itself. Paired measurements, using open respirometry, were done on intact and isolated skin. In normoxic water oxygen uptake across the cutaneous surface was always greater than O2 consumed by isolated skin. Closed respirometry was used to determine the effect of declining water PO2 on cutaneous uptake across intact skin and oxygen consumption by the isolated skin. Both intact skin uptake and isolated skin consumption were related significantly to water PO2 (150-100 mm Hg). Assuming O2 consumption of the isolated skin to be same as in situ, calculations showed that when water PO2 was high (150 mm Hg), about 40% of total cutaneous O2 uptake was consumed by the skin. At low PO2 (100 mm Hg) this figure was about 20%. Thus in the face of declining water PO2, a greater percentage of total cutaneous uptake goes to satisfy the oxygen requirements of other tissues.