The influence of pre-incubation on the rate of iron uptake and of transferrin synthesis by intact isolated rat seminiferous tubules.

It has been reported recently that major kinetic differences exist in the rate of iron uptake and of transferrin synthesis between intact seminiferous tubules and cultured Sertoli cells. To investigate possible causes of these differences, intact isolated rat seminiferous tubules were isolated and pre-incubated overnight. Then the rates of iron uptake and of transferrin synthesis were compared with those of freshly isolated tubules. We found that overnight pre-incubation increased the rate of both processes. Iron depletion was not the cause of these changes, since pre-incubation under iron excess gave comparable results. Possible explanations of these phenomena are discussed.