Uptake of D-mannoheptulose by rat erythrocytes, hepatocytes and parotid cells.
D-[3H]mannoheptulose (or D-[1-14C] mannoheptulose) net uptake was measured in rat erythrocytes, parotid cells and hepatocytes. In the erythrocytes and parotid cells, the intracellular distribution space of the heptose (0.1 mM) represented only about 1 and 13%, respectively, of the intracellular 3HOH space. In hepatocytes, however, it amounted to approximately 45% of the intracellular 3HOH space. In all cases, the apparent distribution space of D-[3H]mannoheptulose hexaacetate largely exceeded that of unesterified D-[3H]mannoheptulose. Relative to the intracellular water space, the generation of acidic metabolites (expressed as an apparent distribution space) from radioactive D-mannoheptulose was one order of magnitude lower in parotid cells (< or = 3%) than in hepatocytes (> or = 20%). These findings are compatible with the hypothesis that D-mannoheptulose is transported into cells mainly, if not exclusively, at the intervention of GLUT2.
Ramirez
R
R
Laboratory of Experimental Medicine, Brussels Free University, Brussels, Belgium.
Courtois
P
P
Ladriere
L
L
Kadiata
M M
MM
Sener
A
A
Malaisse
W J
WJ
D000818:Animals; D002250:Carbon Radioisotopes; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D008356:Mannoheptulose / Q000493:pharmacokinetics*; D010306:Parotid Gland / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013395:Sucrose / Q000493:pharmacokinetics; D014316:Tritium
D002250:Carbon Radioisotopes; D014316:Tritium; D013395:Sucrose; D008356:Mannoheptulose; D005947:Glucose