Effect of several biogenic amines on in vitro progesterone secretion by the bovine corpus luteum

1. The effect of several biogenic amines on secretion of progesterone (P4) was examined using bovine corpora lutea (n = 6), removed on day 13 of the oestrus cycle, enzymatically dispersed and cultured in vitro. 2. Luteal cell cultures were co-incubated with 0, 10, 50 or 100 ng of luteinizing hormone (LH) and 50 ng of epinephrine (EPI), norepinephrine (NOR), dopamine (DOPA), melatonin (MEL), N-acetyl-50H-serotonin (N-acetyl-50H-tryptamine; NacS), serotonin (50H-tryptamine; 5HT) or saline control. 3. EPI, NOR and DOPA decreased baseline release of P4. 4. The magnitude of the response of P4 to LH was depressed when cells were co-incubated with DOPA, EPI and 5HT and stimulated when cells were co-incubated with MEL and NacS. 5. These data indicate that the biogenic amines might modulate ovarian steroidogenesis supplementary to hypothalamic-hypophyseal hormonal mechanisms.