title: Influence of aerobic energy deficit, ouabain and harmaline on the phenylalanine and galactose active transport by snail intestine.
abstract: The effect of anaerobiosis (N2 bubbling of the medium) or 10(-4) M dinitrophenol on the penetration of 0.5 mM Phe in snail and rat everted intestine, in 2 min and 30 min incubation periods, has been studied. The aerobic energy deficit inhibits the amino acid net entry in both species, but whereas the active transport is annulled in rat, snail intestine is capable of continuing to accumulate Phe against a gradient. The prolonged action (30 min of preincubation) of 1 mM ouabain inhibits 0.1 mM Phe and 0.1 mM galactose entry in snail intestine. Amino acid uptake is far higher than the one obtained in the absence of Na+, in which condition Phe keeps accumulating against a gradient in the tissue water. Galactose active transport, instead, becomes null in the presence of the glucoside or in the absence of Na+. One mM harmaline is able to inhibit the initial entry of galactose into the tissue, while higher than 5 mM concentrations are required to inhibit that of Phe. Results confirm that snail intestine is capable of easily carrying out active transport processes with energy from anaerobic origin. On the other hand Phe transport is less sensitive to the absence of Na+, presence of ouabain or harmaline than that of galactose, so that contrary to what has been observed for the sugar, the active transport of the amino acid is not annulled in any of the three conditions.
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D004140:Dinitrophenols / Q000494:pharmacology; D005690:Galactose / Q000378:metabolism*; D006246:Harmaline / Q000494:pharmacology; D007408:Intestinal Absorption / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D010649:Phenylalanine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012908:Snails
chemical_list: D004140:Dinitrophenols; D010649:Phenylalanine; D010042:Ouabain; D006246:Harmaline; D005690:Galactose