Effect of cyclodextrin-encapsulated β-carotene on progesterone production by bovine luteal cells

Experiments were conducted to examine the effect of cyclodextrin-encapsulated β-carotene on basal or cholesterol (cyclodextrin-encapsulated), LH and dibutyryl cyclic AMP (dbcAMP)-stimulated progesterone production by bovine corpus luteum cells isolated from mid-luteal heifer ovaries by collagenase digestion. Cells were cultured with serum-free DMEM/Ham’s F12 medium in serum pre-treated plastic culture dishes for periods of up to 11 days. Medium was replaced after 24 h and thereafter every 48 h. β-Carotene was added to cultures in a carrier molecule, dimethyl-β-cyclodextrin, to facilitate dissolution. All treatments were started on day 3 of culture. Treatment of cells with 1 or 2 μmol/l β-carotene resulted in sharp inhibition of progesterone production. On the contrary, treatment of cells with 0.1 μmol/l β-carotene resulted in significant stimulation ( P