Electrical potentials across isolated small intestine of the rat

¹ Department of Radiation Biology, The University of Rochester, School of Medicine and Dentistry, Rochester, New York

Electrical potential measurements indicated that the absorption of salt across the small intestine was the result of active transport of Na⁺, followed passively by an equivalent of Cl^–. The potential across the intestine was positive on the serosal side and higher in the jejunum than in the ileum. The Na⁺ concentration in the bathing media determined the magnitude of the potential; other monovalent ions had no effect.