l. Studies have been made of the distribution
and excretion of mercury, gold and lead, in
rabbits, without and with treatment with dithiols
The method involves the use of radio- active isotopes of these elements.
After the intravenous injection of 5μM. /kg.
of mercuric chloride, the highest concentrations
of mercury were found in the kidneys. Of the
other tissues, only the liver contained more than
one microgramme of mercury per gramme consistently. The excretion of mercury was slow and
accounted for only two-thirds of the dose after
two weeks, occurring mainly in the urine.
After treatment with dimercaprol, much
smaller amounts of mercury were found in the
kidneys. The excretion of mercury in the urine
was greatly enhanced, but the faecal excretion
was unaffected. These changes were found even
when treatment was delayed until nine days after
Similar changes occurred after the administration of dimercaprol glucoside, except that
the concentrations of mercury in the plasma, and
the biliary excretion, increased. The urinary
excretion of mercury was less than that obtained
after treatment with dimercaprol.
After the intravenous injection of 0.01mó./
kg. of gold chloride, high concentrations of gold
were found in the spleen, kidneys, plasma, bone
marrow, liver and bile. Excretion occurred very
slowly, about one -fifth of the dose being eliminated in the urine and faeces in five days.
After treatment with dimercaprol, the concentrations of gold in the blood were reduced and
the urinary and biliary excretion increased. No
substantial change occurred in the amounts of
gold found in other tissues, or in the faecal
High concentrations of lead were found in
the liver, spleen, bone marrow, epiphyses, and
kidneys, twenty -four hours after the intravenous
injection of 0.01mM./kg. of lead acetate. Only
1-4 per cent of the dose was excreted in the
urine in this period.
After the administration of dimercaprol
glucoside, the quantities of lead in the liver
and blood cells decreased. This was accompanied
by increased urinary and biliary excretion of
5. Both dimercaprol and dimercaprol glucoside
increased the urinary excretion of lead after the
injection of O.1mM./kg. of lead acetate, and were
approximately equally effective.
6. After the intravenous injection of 0.01mM./kg.
of lead acetate, treatment with 1:4-dithioerythritol slightly, and with 1:3- dimercaptopropanol
greatly, increased the urinary excretion of lead.
7. Twenty -one days after the intravenous injection of 0.01mM./kg. of lead acetate, about 50 per
cent of the dose had been excreted, predominantly
in the faeces, and the bones contained about
25 per cent of the dose. The bone marrow and
the liver were the only other tissues which consistently contained more than 1 per cent.
Treatment with dimercaprol or parathyroid
extract or both, caused no substantial change in - the distribution or the excretion of lead, apart
from a transient increase in the urinary excretion
8. The method and the significance of these
results are discussed.