Metabolism of n-alkanes and their incorporation into lipids in the rainbow trout.

The metabolic utilization by fish of n-alkanes was investigated in Salmo gairdneri R. receiving per os a single dose of [14C]heptadecane. This alkane was largely absorbed and radioactivity in the intestinal content was entirely in heptadecane. No elimination of the hydrocarbon was observed in urine. One week after dosing, ca. 50% of the ingested radioactivity was stored in the carcass and two-thirds of this radioactivity was due to heptadecane. The highest concentration of 14C was found in adipose tissue and liver, in which 77 and 22%, respectively, of the radioactivity originated from hydrocarbon. The rest was omega-oxidized to heptadecanoic acid. This fatty acid was incorporated into neutral lipids (mainly as free fatty acid) and phospholipids.