Effect of ethanol and other alcohols on the transport of amino acids and glucose by everted sacs of rat small intestine

Abstract

1. 1. Using everted sacs of rat small intestine, 3% ethanol was found to inhibit the transport of l-phenylalanine, l-leucine, glycine, l-alanine, l-methionine, and l-valine. The transport of d-glucose was partially inhibited. 2. 2. Similar effects of l-phenylalanine transport were observed with 3% methanol; 2% n-propanol and isopropanol; 1% n-butanol and isobutanol and with 0.5% cyclohexanol and phenethyl alcohol. 3. 3. The effect of ethanol on l-phenylalanine transport increased with ethanol concentration, and was reversed by washing the section of intestine with buffer solution following exposure to ethanol. 4. 4. Ethanol produced some increase in the permeability of the everted sac in 1 h, as measured by diffusion of d-phenylalanine. 5. 5. The rapid inhibition of amino acid transport, the ease of reversibility of this inhibition, and the relatively small increase in back-diffusion, indicate that ethanol inhibits active transport under the conditions of these experiments.