Depression of iron uptake from transferrin by isolated hepatocytes in the presence of ethanol is a pH-dependent consequence of ethanol metabolism.
Incubation of freshly isolated rat hepatocytes with highly purified radiolabeled rat transferrin in weakly buffered medium in the presence of 10 mM ethanol resulted in a marked diminution of iron uptake by these cells, associated with a greater pH depression than in ethanol-free control studies. This effect on iron uptake persisted, even when the cells were preincubated for 90 min with ethanol before the addition of transferrin. Increasing the buffering capacity of the system or the addition of a metabolic inhibitor of alcohol dehydrogenase (4-methylpyrazole) returned iron uptake to control values. Acetaldehyde, acetate, lactate (products of ethanol metabolism), and 3-butanol (an alcohol not metabolized by alcohol dehydrogenase) had no influence on iron uptake. Further investigation of iron uptake over the pH range 6-8.5 revealed a marked dependency of iron uptake on the extracellular pH. Leucine incorporation into cell protein was also found to be pH dependent. It is suggested that, in the light of current understanding of transferrin recycling by other cell types, the disturbances of iron homeostasis observed in alcoholics can be partially accounted for by alterations in their acid-base metabolism.
D000079:Acetaldehyde / Q000494:pharmacology; D000818:Animals; D000431:Ethanol / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000378:metabolism*
D014168:Transferrin; D000431:Ethanol; D007501:Iron; D000079:Acetaldehyde