Estrogens and androgens affect human luteal cell function.

OBJECTIVE: To evaluate estrogens (Es)--E2, estrone (E1), and estriol--and androgens--T and androstendione (A)-effect on P, prostaglandin (PG) F2α, PGE2, and vascular endothelial growth factor (VEGF) release and on VEGF expression in human luteal cells. To elucidate whether androgens effects were direct or mediated by their conversion in Es, an aromatase inhibitor was used. Finally, the luteal effect of the non-aromatizable dihydrotestosterone was evaluated. DESIGN: Prospective laboratory study. SETTING: University hospital. PATIENT(S): Corpora lutea (CLs) were obtained from 36 normally menstruating patients in the midluteal phase of the menstrual cycle. INTERVENTION(S): The human luteal cells were isolated from CLs and primary cultures were established. MAIN OUTCOME MEASURE(S): P and PG release were assayed by enzyme immunoassay; VEGF secretion by ELISA; VEGF messenger RNA (mRNA) expression by real-time polymerase chain reaction (PCR). RESULT(S): P and PGF2α secretion were decreased by Es and androgens. The VEGF release was increased by Es and androgens, whereas VEGF mRNA expression was not. The aromatase inhibitor counteracted T and A luteal effects. CONCLUSION(S): Both Es and androgens could participate in the regulation of human luteal function. The effect of T and A seems to be mediated by their conversion to Es, whereas for dihydrotestosterone, both direct androgenic and indirect estrogenic luteal effects could coexist.

Effects of high density lipoprotein containing high or low beta-carotene concentrations on progesterone production and beta-carotene uptake and depletion by bovine luteal cells.

Luteal cells were isolated from mid-luteal heifer ovaries by collagenase digestion. Cells were cultured with DMEM/Ham's F12 medium in serum pre-treated plastic culture dishes for periods of up to 11 days. As beta-carotene is almost completely insoluble in all polar solvents, it was added to cultures in either dimethyl sulphoxide (DMSO), tetrahydrofuran (THF) or as high-density lipoprotein (HDL) containing high or low beta-carotene concentrations. Medium was replaced after 24 h, thereafter medium was changed every 48 h. Treatment of cells with DMSO alone or with beta-carotene (5 micromol/l) in DMSO both resulted in significant (P<0.01) stimulation of progesterone production. beta-Carotene (5 micromol/l) in THF did not alter progesterone production but 50 micromol/l beta-carotene in THF resulted in significant inhibition (P<0.02) of progesterone production on days 3 and 7. Cultures were also supplemented with bovine HDL preparations containing equal concentrations of cholesterol (25 microg/ml) but high or low beta-carotene (12.4 or 0.44 microg/mg of cholesterol). Both HDL preparations significantly stimulated progesterone production (P<0. 001) but the high beta-carotene HDL was significantly (P<0.02) more effective than the low beta-carotene HDL. However, when given together with bovine luteinizing hormone (bLH) or dibutyryl cAMP (dbcAMP), the high beta-carotene HDL stimulated progesterone production less than did the low HDL (P<0.01). Uptake and depletion of beta-carotene by luteal cells were also examined in culture. beta-Carotene supplementation increased luteal cell beta-carotene from an initial level of 373 ng per 10(6) cells to 2030 ng per 10(6) cells by day 6. In contrast, the levels in control cells decreased to 14% of starting values during the same period. Cells treated with HDL containing high beta-carotene on day 1 or days 1 and 3 were then incubated with or without bLH or dbcAMP for a further 2 days to investigate the effect of bLH and dbcAMP on depletion of beta-carotene by luteal cells. beta-Carotene depletion in the luteal cells was significantly higher (P<0.05) in LH- and dbcAMP-treated cells than in the control cells in both groups. These results indicate that the use of solvents such as DMSO or THF may have undesirable effects due to alteration of cell membrane permeability. Supplementation with bLH or dbcAMP may increase the metabolism of beta-carotene in luteal cells. bLH or dbcAMP together with high beta-carotene HDL may, when combined with the effect of increased beta-carotene metabolism, give less stimulation than with low beta-carotene HDL.