Short-circuit current and total conductance measurements on rabbit ileum.

1. Short-curcuit current (SCC) and total conductance (Gt) measurements were made in in vitro preparations of rabbit terminal ileum. 2. Successive additions of D-glucose increased the SCC and Gt in a stepwise way and both effects were seen to correlate linearly. 3. Measurements of SCC ant Gt were also made after replacing Na in the Krebs solution by K or sucrose. The SCC decreased to nearly zero in both cases but the decrease in Gt was larger when sucrose was used. 4. SCC and Gt were monitored after the addition of ouabain. SCC decreased to nearly zero but Gt remained constant. 5. On successive additions of sucrose after the preparation was mounted in 1/4 Na Krebs without osmolal compensation, SCC decreased and Gt increased, a linear relationship being found between both changes. 6. Successive additions of 2-deoxy-td-glucose caused a stepwise decrease of SCC and an increase in Gt. These effects seemed independent of the presence of glucose. 7. A model in which a resistance in series is added to the basic model by Ussing & Windhager (1964), modified by Rose & tschultz (1971), is proposed to account for these findings.