“…A number of other studies, however, argue convincingly against any physiologically significant simple diffusional component of either hexose or amino acid transport. Thus in two patients with congenital glucose-galactose malabsorption little or no glucose was absorbed during intestinal perfusion of high concentrations of glucose, maltose or sucrose[69,70], and little or no amino acid was absorbed during intestinal perfusion of lysine and arginine in cystinuria [21, 23].One possibility not so far considered is that the experimental technique used by Matthews et at.…”