Effect of Escherichia coli endotoxin on ascorbic acid transport in isolated adrenocortical cells.
The active uptake of ascorbic acid by isolated rat adrenocortical cells increases with ascorbic acid concentration, depends on time and calcium, and is inhibited by ACTH concentrations required for maximal steroidogenesis. Lipopolysaccharide of Escherichia coli 0111:B4 modifies the ascorbic acid uptake in a calcium-dependent manner. At low calcium concentrations, lipopolysaccharide exerts a stimulatory effect on ascorbic acid transport and at high concentrations lipopolysaccharide produces a dose-dependent inhibitory effect. This inhibition of the ascorbic acid transport by the endotoxin can alter the ascorbic acid accumulation in the adrenal gland during endotoxin shock.
Garcia
R
R
Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense, Madrid, Spain.
Municio
A M
AM
D000302:Adrenal Cortex / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014783:Viscosity
D004731:Endotoxins; D008070:Lipopolysaccharides; C044101:endotoxin, Escherichia coli; D001205:Ascorbic Acid; D002118:Calcium