UPTAKE, DISPOSITION, AND PERSISTENCE OF ACRYLONITRILE IN RAINBOW-TROUT

The uptake and disposition of [2,3-C-14]acrylonitrile-derived C-14 wer e studied in rainbow trout by water exposure. Trout were exposed to [C -14]ACN at 5.3 mu g/liter and sampled at various times during a 24-hr uptake phase. After transfer to fresh water, fish were sampled to 72 h r for the estimation of elimination rates and the half-life of C-14. T hroughout these experiments several fish were also sacrificed for whol e-body autoradiography. The uptake of C-14 in carcass and viscera bega n to level off at 24 hr and the apparent bioconcentration factor was l ow and of the order of 3-4. In the elimination studies, the C-14 appea red to persist in both muscle and visceral tissue for a longer time th an anticipated based upon its octanol-water partition coefficient (log p = -0.92). The t(1/2) of C-14 in muscle in two such experiments was calculated to be 117 and 102 hr. The autoradiographs of whole-body sec tions of exposed trout also revealed a slow loss of C-14 from muscle. Muscle extracts prepared from exposed fish were essentially nondialyza ble. When dialyzed muscle extract was analyzed for protein and C-14 af ter SDS-PAGE electrophoresis, most of the C-14 was associated with a s ingle protein band with a mobility comparable to standards in the 10,0 00 Dalton range. These studies indicate that the long half-life of C-1 4 seen in trout muscle may be due to covalent binding of C-14 to a pro tein with a molecular weight of approximately 10,000 Daltons. (C) 1995 society of Toxicology