Monosaccharide transport into hemocytes of a sipunculan worm Themiste dyscrita

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · Am. J. Physiol.; (United States)

OSTI ID:5246908

Ingermann, R L; Hall, R E; Bissonnette, J M; Terwilliger, R C

The hemerythrin-containing blood cells, or hemocytes, of the sipunculan worm Themiste dyscrita were found to have a stereospecific and nonconcentrative monosaccharide transport system. The transport system transferred both D-glucose and 3-O-methyl-D-glucose (3-OMG), and transport into cells by this system was rapid, reaching 50% equilibrium in approximately 20 s at 10 degrees C with an initial concentration gradient of 0.1 mM; the contribution to total uptake by simple diffusion was very small. 3-OMG uptake showed saturation kinetics with a low half-saturation constant (Km less than or equal to 0.1 mM). The uptake of labeled 3-OMG by the hemocytes was strongly inhibited by unlabeled 3-OMG, 2-deoxy-D-glucose, alpha- and beta-D-glucose, D-galactose, and D-mannose. It was moderately inhibited by D-xylose, only slightly by alpha-methyl-D-glucoside and D-fructose, and uninhibited by sucrose, L-glucose, or D-sorbitol. Phloretin was more potent than phloridzin in blocking entry of 3-OMG. Cytochalasin B did not bind tightly to the T. dyscrita transporter and was not a potent inhibitor of transport; it half-maximally inhibited 3-OMG transport at 0.1 mM. Therefore, despite some differences the data suggest functional similarities in the mechanism of monosaccharide transport into blood cells of mammals and this invertebrate.

• Research Organization: Oregon Health Sciences Univ., Portland
• OSTI ID: 5246908
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States); ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ASCHELMINTHES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
DIFFUSION
DISACCHARIDES
DIURETICS
DRUGS
FRUCTOSE
GALACTOSE
GLUCOSE
GLYCOSIDES
HELMINTHS
HEXOSES
ISOTOPE APPLICATIONS
KETONES
KINETICS
LABELLED COMPOUNDS
MANNOSE
MATERIALS
MEMBRANE TRANSPORT
MONOSACCHARIDES
NEMATODES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PENTOSES
PHLORIZIN
REACTION KINETICS
RESPONSE MODIFYING FACTORS
SACCHARIDES
SACCHAROSE
SORBITOL
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
XYLOSE