Transapical Na+ electrochemical potential difference and solute accumulation in Aplysia californica enterocytes

Extracellular water averaged 20% of total intestinal water. The sugar, D-galactose, was accumulated by the Aplysia enterocytes. The amino acids glycine, L-alanine and alpha-aminoisobutyric acid (AIB) were all accumulated by the Aplysia enterocytes. The electrochemical potential difference for Na+ across the mucosal membrane of Aplysia enterocytes was energetically adequate in driving D-galactose, L-alanine, glycine or AIB uphill into the Aplysia enterocytes.