The pharmacokinetics of labelled DMPS (sodium-1,3 ''C-2,3-dimercaptopropane-1sulphonate) have been studied in four beagle dogs following bolus intravenous injection (65.7 pmol kg-') and oral administration (197 pmol kg-'). Following intravenous injection the main kinetic parameters were t* = 43min, Ve = 160ml kg-', and plasma clearance C1, = 2.6mlmin-'kg-'.
Following oral administration I4C-DMPS is rapidly absorbed with peak concentrations (478 f 25 Fmol1-') measured after 3 M 5 min. About 60 per cent of the oral dose was absorbed. Estimates of tt, V , and C1, after oral administration were in close agreement with the values obtainel in the intravenous study.
I4C-DMPS is eliminated from the body by the kidneys. About 70 per cent of I4C-DMPS in dog plasma are bound to proteins. Binding is even higher in plasma from rat and man.
KEY WORDS Dimercaptopropanesulphonate (DMPS) Pharmacokinetics Plasma protein binding
MATERIALS AND METHODS
Chemicals
Both DMPS and 14C-DMPS (specific activity: 87 pCimmol-' were donated by the manufacturer*). Data relating to the purity of the DMPS batches used in