Effect of transmucosal fluid movement on zinc and copper absorption from the rat small intestine

1. The effects of transmucosal fluid movement on zinc and copper absorption from rat small intestine were investigated using an in situ recirculating perfusion method. 2. Transmucosal fluid movement was obtained by using hypo-, iso- or hyperosmotic perfusate containing various concentrations of sodium chloride. Linear correlations were obtained between net fluid movement and absorption rate constants, which were calculated from the perfusion decline of zinc (n = 15; r = 0.77) and copper (n = 15; r = 0.75). 3. The changes in serum levels of these metals did not correlate with the increase in the absorption rate. 4. The present study indicates that zinc and copper absorption is dependent on transmucosal fluid movement.