Abstract

Increased permeability of the intestinal mucosa to small molecules and ions has previously been proposed as a mechanism causing the profuse diarrhoea characteristic of Asiatic cholera. A technique for measuring absorption rates of ¹⁴C-urea and ³H-arabinose has been employed to study jejunal permeability during experimental canine and naturally acquired human cholera. The ratio of the absorption rates of these two solutes of different size is an expression of intestinal membrane selectivity and permits calculation of an equivalent pore radius. No change of membrane selectivity was observed in canine loops after challenge with cholera toxin. During naturally acquired human cholera, jejunal pore size was not significantly different from that measured during convalescence. This method was demonstrated to be sensitive to changes induced by amphotericin B, an antibiotic known to alter membrane permeability and selectivity. These data are inconsistent with the hypothesis of increased intestinal permeability during cholera.