Lipid accumulation is a hallmark of corpus luteum regression and we characterized lipids stored in rat corpora lutea of pregnancy between days 21 and 24 post coitum, the period of luteolysis. A 10-fold rise in lutein triglyceride concentrations occurred between days 21 and 24, which represented the major alteration in luteal lipid metabolism during luteolysis, coinciding with the appearance of ...