Effect of cyclodextrin-encapsulated beta-carotene on progesterone production by bovine luteal cells.
Experiments were conducted to examine the effect of cyclodextrin-encapsulated beta-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 24h and thereafter every 48 h. Beta-carotene was added to cultures in a carrier molecule, dimethyl-beta-cyclodextrin, to facilitate dissolution. All treatments were started on day 3 of culture. Treatment of cells with 1 or 2 micromol/l beta-carotene resulted in sharp inhibition of progesterone production. On the contrary, treatment of cells with 0.1 micromol/l beta-carotene resulted in significant stimulation (P<0.05) of both basal and cholesterol-stimulated progesterone secretion. The effect of beta-carotene on LH or dbcAMP-stimulated progesterone production was also examined. Treatment of cells with LH or dbcAMP always resulted in stimulation of progesterone secretion (P<0.001). However, cells treated with LH plus beta-carotene or dbcAMP plus beta-carotene both produced significantly (P<0.01) less progesterone relative to those cells treated with LH or dbcAMP alone on days 7, 9 and 11 of culture. These results indicate that beta-carotene can enhance luteal steroidogenesis when present at low concentrations but is inhibitory at higher concentrations and that encapsulation of beta-carotene in cyclodextrin is an effective method of supplying it to cells in culture.
Arikan
S
S
Department of Animal Physiology and Nutrition, University of Leeds, Leeds LS2 9JT, UK. sevket95@hotmail.com
Rodway
R G
RG
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002214:Capsules; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism*; D003505:Cyclodextrins; D004337:Drug Carriers; D005260:Female; D007986:Luteinizing Hormone / Q000096:biosynthesis; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D011374:Progesterone / Q000096:biosynthesis*; D019207:beta Carotene / Q000494:pharmacology*
D002214:Capsules; D003505:Cyclodextrins; D004337:Drug Carriers; D019207:beta Carotene; D011374:Progesterone; D003994:Bucladesine; D007986:Luteinizing Hormone