Competitive kinetics of sugar active transport in snail intestine.
Everted intestinal rings of the snail Cryptomphalus hortensis accumulate labelled sugars against a concentration gradient. The active transport of D-galactose (KT = 3.6 mM) is competitively inhibited by D-glucose (Ki = 8.2 mM) and by 3-0-methylglucose (Ki = 24 mM), but it is not affected by L-arabinose, D-fructose, L-arabinose and D-mannitol penetrate into the tissue at the same rate, they do not develop accumulation gradient, and all of them follow the kinetics of a diffusion process. D-glucose, on the contrary, like galactose, penetrates much more quickly and accumulates against a gradient.
D000818:Animals; D001089:Arabinose / Q000378:metabolism*; D001693:Biological Transport, Active; D005632:Fructose / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism*; D007408:Intestinal Absorption; D008353:Mannitol / Q000378:metabolism*; D012908:Snails / Q000378:metabolism*
D006601:Hexoses; D005632:Fructose; D008353:Mannitol; D001089:Arabinose; D005947:Glucose; D005690:Galactose