The disposition of [14C]acrylonitrile in rats.

1. The disposition of [1,2-14C]acrylonitrile and acrylo[14C]nitrile has been studied following intraperitoneal and oral administration to rats. 2. Most of the 14C found in the tissues was associated with erythrocytes, liver and kidneys. Loss of 14C from liver and kidneys occurred fairly rapidly, but the 14C in the erythrocytes was still mostly retained 48 h after administration. Significant differences in the rates of 14C loss from tissues occurred with [1,2-14C]acrylonitrile and acrylo[14C]nitrile given orally. 3. The 14C from both labelled forms of acrylonitrile was excreted mostly in the urine (82-93% dose) with a smaller amount exhaled unchanged in the breath (3-7% dose) in 24 h.