EPITHELIAL BARRIER AND ION-TRANSPORT IN CELIAC SPRUE - ELECTRICAL MEASUREMENTS ON INTESTINAL ASPIRATION BIOPSY SPECIMENS

Epithelial barrier function and ion transport was studied in coeliac s prue using a miniaturised Ussing device for measurements on diagnostic aspiration biopsy specimens from the jejunum of untreated or gluten f ree nourished sprue patients, or from healthy controls. Pure epithelia l resistance (Re) indicating epithelial barrier function was determine d by transmural alternating current impedance analysis. It was reduced by 56% in acute sprue mean (SEM) (9 (1) Omega . cm(2)) compared with controls (20(2) Omega . cm(2)). In gluten free nourished sprue patient s Re was only partly recovered (15 (1) Omega . cm(2)). Subepithelial r esistance (R(sub)) was also changed from 28 (1) Omega . cm(2) - in con trol to 17 (1) Omega . cm(2) in acute sprue because of the change in m ucosal architecture, but was unchanged in gluten free nourished sprue patients (29 (4) Omega . cm(2)). In acute sprue, unidirectional Na+ an d Cl- fluxes were increased in both directions as a consequence of the decreased resistance. However, short circuit current (I-SC) as Well a s Na+ and Cl- net fluxes were not significantly different from control . Subsequently, the electrogenic Cl- secretory system was investigated . After maximal stimulation with theophylline and prostaglandin E(1), a Cl- - dependent increase in Ise was obtained in the sprue mucosa and control jejunum. It showed saturation characteristics and was blockab le by serosal bumetanide. When compared with control, neither K-m nor V-max of this electrogenic Cl- secretion was significantly changed in coeliac sprue. In conclusion, a miniaturised Ussing device was used fo r transport measurements on intestinal biopsy specimens. In acute coel iac disease, the epithelial barrier of the jejunum was seriously distu rbed. The active electrogenic Cl- secretory transport system was prese nt in the sprue mucosa, but was not activated in the Ussing chamber in vitro when compared with control jejunum.