Preventive and therapeutic effects of thiamine, ascorbic acid and their combination in lead intoxication.

Thiamine, ascorbic acid and their combination were investigated for their ability to prevent or treat the experimental lead intoxication in rats. The combination of the two vitamins was most effective in reducing the lead induced inhibition in the activity of blood delta-aminolevulinic acid dehydratase, elevation in the level of blood zinc protoporphyrin and the urinary excretion of delta-aminolevulinic acid and the uptake of lead in blood, liver and kidney. The combined treatment post lead exposure was also most effective in restoring the lead induced biochemical alterations and mobilizing lead from the tissues. The order of effectiveness was, thiamine + ascorbic acid less than ascorbic acid less than thiamine. The lead induced changes in brain biogenic amines and the brain concentration of lead remained unaffected by these vitamins.