Ion transport in normal and inflamed human jejunum in vitro. Changes with electric field stimulation and theophylline.

We studied ion transport in human jejunal mucosa under basal conditions and when tissues were stimulated electrically (EFS) and with theophylline 5 mM (N = 12 pairs). Tissues were mounted in a flux chamber to measure unidirectional fluxes of 22Na, 36Cl, short-circuit current, Isc (mueq/cm2/hr), electrical potential difference, PD (mV), and total ionic conductance, G (mS/cm2). Six pairs of tissues that were normal or less inflamed responded to theophylline by increasing PD and Isc and by reducing JCl(ms), the mucosal to serosal flux of Cl. In six pairs that did not respond to theophylline or to EFS, inflammation was more intense, and in the basal state, G was lower, PD was higher, and unidirectional fluxes of Na and Cl were halved. We conclude: (1) normal jejunum secretes Cl and responds to theophylline or EFS by reducing JCl(ms) thereby increasing Cl secretion; (2) unlike human ileum, neither theophylline nor EFS affect JCl(sm); (3) inflammation eliminates the response to theophylline and to EFS.