Epithelial glucose transport by lobster antennal gland

摘要: Transport of d-[3H]glucose into lobster (Homarus americanus) brush-border membrane vesicles (BBMVs) prepared by Mg2+ precipitation from antennal gland labyrinth-coelomosac tissue was examined. Influx d-glucose occurred primarily a phlorizin-sensitive, Na+-dependent carrier similar to that found in vertebrate renal epithelium. An inwardly directed Na+ gradient drove concentrative uptake, whereas gradients Li+ and K+ did not. Stimulation the further enhanced imposition an inside-negative potential difference also increases pH vesicle incubation media. analysis cis inhibition uptake number sugars sugar derivatives indicated transporter requires (a) substrate be d-pyranose C1 chair conformation (b) hydroxyl groups at C2 C3 ring unmodified equatorial. Apparent kinetic parameters for glucose were determined under zero-trans, short-circuited conditions. Maximal influx estimated 96 pmol mg-1 protein s-1. Half-maximal occur 0.20 mmol l-1 d-glucose. The relationship between external concentration sigmoidal, stoichiometry transport 3 Na+:1 using static head method.