Influence of dopamine as noradrenaline precursor on the secretory function of the bovine corpus luteum in vitro.

1. Dopamine is assumed to affect the ovary function after its conversion into noradrenaline (NA). 2. To study this bovine luteal slices from 11-14 days of the oestrous cycle were preincubated for 24 h to recover beta-receptors and next they were incubated for 1, 2 or 4 h with (a) different doses of dopamine; (b) dopamine together with a beta-antagonist (propranolol) or with a dopamine receptor blocker (droperidol); (c) dopamine with a dopamine-beta-hydroxylase inhibitor. 3. Dopamine stimulated the luteal content of oxytocin (OT) and progesterone. This effect was inhibited by propanolol but not by droperidol. 4. Dopamine added to the medium was followed by an increase of noradrenaline there. This rise was dose and time-dependent. 5. The dopamine-beta-hydroxylase inhibitor, inhibited the stimulating effect of dopamine on luteal progesterone and OT content. 6. Bovine corpus luteum can synthesize de novo NA from dopamine as a precursor.