The Exchange of Iron with Interstitial Fluid.

The extravascular labile iron pool of the preerythropoietic phase of iron metabolism has been demonstrated to be the interstitial fluid compartment. There is no direct means of measuring total iron turnover in interstitial fluid. From the evidence presented one may conclude that interstitial fluid iron turnover per day is at least as great as the size of the plasma iron pool but probably less than the plasma iron turnover itself.