Disposition of propargyl alcohol in rat and mouse after intravenous, oral,dermal and inhalation exposure

1. The disposition of propargyl alcohol (PAL) radiolabelled with carbon-14 ([2,3-C-14]PAL) was determined in the F344 rat and B6C3F(1) mouse following intravenous oral, inhalation and dermal exposure. 2. By 72 h following an i.v. (1 mg kg(-1)) or oral (50 mg kg(-1)) dose, 76- 90% of the dose was excreted. Major routes of excretion by rat were urine ( 50-62%), CO2 (19-26%) and faeces (6-14%). Major routes of excretion by mous e were urine (30-40%) CO2 (22-26%) and faeces (10-20%). Less than 6% of the dose remained in tissues at 72 h. Biliary excretion if radioactivity by ra t (62% in 4 h) was much greater than elimination in faeces (6% in 72 h), in dicating that PAL metabolites underwent extensive enterohepatic recycling. 3. Dermal exposure studies demonstrated that dermal absorption of PAL was m inimal due to its inherent volatility. 4. In the inhalation studies (1, 10 or 100 ppm for 6 h), 23-68% of the radi oactivity to which animals were exposed was absorbed. The primary route of excretion was urine (23-53%), and a significant portion was exhaled as vola tile organics (15-30%). 5. PAL was extensively metabolized by both species. One metabolite was iden tified as 3,3-bis[(2-(acetylamino)-2-carboxyethyl)thio]-1-propanol, which i s consistent with Banijamali et al. (1999).