Long-term effects of partially hydrogenated herring oil on the rat myocardium

Male Sprague-Dawley rats were fed semisynthetic diets containing 25% (w/w) experimental lipid. A partially hydrogenated herring oil (PHHO), containing 25% C22:1 as an isomeric mixture dominated by cetoleic (cis-docos-11-enoic), but partially altered to the trans form and containing other positional isomers, was compared with lard:corn oil 3:1(LCO) (w/w). The feeding period extended up to 111 weeks. Ten animals from both groups each were sacrificed at 2, 8, 16, 24, and 32 weeks. The remaining animals from each group were kept on the diets either until spontaneous death occurred or until Week 111. The LCO rats had higher serum cholesterol levels. The PHHO rats had transient myocardial lipidosis and very severe, progressive myocardial inflammation and scarring.