Suggestive evidence for a DA D3 receptor-mediated increase in the release of oxytocin in the male rat.

ABSTRACT

The dopamine (DA) D2/3 receptor agonists quinpirole (0.5-8.0 mg kg-1, s.c.) and 7-OH-DPAT (0.2-3.2 mg kg-1, s.c.), but not the preferential DA D2 receptor agonist bromocriptine (2.0-32.0 mg kg-1, s.c.), produced increased plasma oxytocin levels in the rat. In keeping with their affinity for the DA D2 receptor, all three compounds produced a marked suppression of plasma prolactin levels in their respective dose range. It is suggested that DA D3 receptors are involved in mechanisms regulating oxytocin secretion in the rat.