Beneficial effects of S-adenosyl-L-methionine on aminolevulinic acid dehydratase, glutathione, and lipid peroxidation during acute lead-ethanol administration in mice

Beneficial effects of S-adenosyl-L-methionine (SAM) in preventing inhibitio n of blood delta-aminolevulinic acid dehydratase (ALAD), alterations in blo od and hepatic glutathione (GSH), hepatic and brain malondialdehyde (MDA) f ormation, and uptake of lead following acute lead plus ethanol coexposure w ere investigated in mice. Whereas exposure to both lead or ethanol individu ally produced a significant inhibition of blood delta-aminolevulinic acid d ehydratase (ALAD) activity, ethanol administration alone produced only a ma rginal depletion of hepatic glutathione (GSH). A significant elevation of h epatic MDA concentration was observed following lead or ethanol ingestion. An appreciable increase in brain GSH following ethanol administration where as a moderate elevation in MDA level following lead plus ethanol administra tion was observed. Combined lead plus ethanol exposure produced a more pron ounced depletion of blood ALAD activity and an increase in hepatic MDA leve l compared to lead- or ethanol-alone administration. Brain GSH concentratio n showed an increase compared to untreated control animals or lead-alone-ex posed mice. Concomitant administration of SAM partially reversed the inhibi tion of blood ALAD activity in all three exposed groups (i.e., lead, ethano l, or lead plus ethanol). Lead concentration in blood, liver, and brain was significantly reduced by SAM in lead-alone or lead plus ethanol coexposed groups. The results suggest that supplementation of SAM may have beneficial effects in preventing alterations in some biochemical variables and accumu lation of lead in blood, liver, and brain during acute lead plus ethanol ex posure in animals. (C) 1999 Elsevier Science Inc. All rights reserved.