Functional dopamine-1 receptors and DARPP-32 are expressed in human ovary and granulosa luteal cells in vitro.

The catecholamines norepinephrine and dopamine (DA) are present in the human ovary; in particular, in follicular fluid. Norepinephrine activates ovarian α- and β-adrenergic receptors and modulates ovarian steroidogenesis, but the significance of ovarian DA is unclear. We examined whether a DA receptor of the D1-subtype (D1-R) is present in human ovary and in cultured human granulosa luteal cells (GC). Using RT-PCR, we cloned complementary DNAs from adult human ovarian and GC messenger RNAs, which are identical to the human D1-R sequence. In ovarian sections, D1-R protein was identified (by immunohistochemistry) in granulosa cells of large antral follicles, cells of the corpus luteum, as well as in cultured GC. An immunoreactive band of approximately Mr 50,000 was found in cultured luteinized GC using the same antiserum in Western blots. The D1-R in these cells was functional, because DA, alone or in the presence of the β-receptor antagonist propranolol, caused cellular contraction. The selective D1-R agon...