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.