Gamma radiation affects active electrolyte transport by rabbit ileum: basal Na and Cl transport

The effect of whole-body gamma radiation (5-12 Gy) on electrolyte transport by rabbit ileum in vitro was assessed for 1-96 h postirradiation using the short-circuit technique and radioisotopic fluxes. Although there was no effect of radiation on short-circuit current (Isc), transepithelial potential, or resistance 1 h after exposure, by 24 h the basal parameters of ileal segments isolated from irradiated animals were significantly greater than those of sham-irradiated controls. The Isc increased in a dose-dependent fashion and was greatest 24 h postexposure. Isotope flux experiments revealed that the increased Isc following irradiation resulted in part from a stimulation of active serosal-to-mucosal net Cl flux. There was no observable change in net Na transport. The results demonstrate that radiation exposure alters cellular transport processes, which may contribute to the fluid and electrolyte imbalance observed following radiation exposure.