An evaluation of perfusion techniques in the study of water and electrolyte absorption in man: the problem of endogenous secretions.

The magnitude of endogenous contamination of various perfusion techniques used to study water and electrolyte absorption in humans was examined indirectly by comparing rates of water and sodium absorption from saline and glucose-saline mixtures administered by both the double-lumen and triple-lumen techniques. Both perfusion systems are pictured, and their construction described. Double-lume was used in 16, and triple in 13 normal subjects. Both methods gave simiar quantitative rates of water and sodium absorption, suggesting that contamination is negligible in normal fasting upper jejunum. However, absorption of solute and water by the proximal segment of the triple-lumen tube apparatus produced difficulties in experimental technqiue; without this controlled, the results were not interpreted further. The double-lumen tube perfusion system is recommended by default.