Does chicken rectal adaptation to a low nac1 diet involve changes in paracellular permeability?

Abstract

1. 1. The electrical parameters (PD and I sc) of the chicken rectum were studied in vitro, in birds fed either a high or a low NaCl diet. 2. 2. Chickens fed a high NaCl diet showed serosa negative values of PD and I sc(− 2.6 mV and − 39.2 μA/cm 2, respectively), being unaffected by the suppression of Na + in the incubation medium. 3. 3. Chickens fed a low NaCl diet had serosa positive values of PD and I sc (4.7 mV and 128.7 μA/cm 2, respectively). In these animals, the reduction of Na + concentration in the incubation medium produced a significant fall in both PD and I sc supporting the view that the adapted rectum is capable of net sodium transport from the mucosal to the serosal compartment. 4. 4. In high-Nad fed chickens, 2,4,6-Triaminopyrimidine added to the mucosal solution resulted in a reverse PD and I sc, suggesting that changes in the paracellular permeability to cations play a role in the rectal adaptation to the sodium content of the diet.