The Involvement of Dopamine in the Regulation of Steroido-genesis in Rat Ovarian Cells

Abstract

To investigate a role for dopamine (DA) in steroidogenesis in the rat ovary, ovarian cells of pregnant-mare-serum gonadotropin (PMSG)-treated rats were incubated with DA agonists, antagonists, adrenergic drugs and β-blocker for 1 h. DA, norepinephrine (NE) and isoproterenol (Iso) increased the level of progesterone (P₄) and cAMP in the conditioned medium. D₁ agonists (SKF38393, SKF82526J, CY208-243) increased P₄ secretion, while the D₂ agonist, bromocriptine, showed no significant effect on P₄ secretion. The effect of NE or Iso was inhibited by the β-blocker proplanolol (Pro), but was not suppressed by the D₂ antagonist, domperidone. The effects of D₁ agonists were suppressed by bulbocapnine (Bul), while neither Pro nor the D₂ antagonist, domperidone, affected the levels of P₄. The D₁ receptor was demonstrated in the PMSG-treated rat ovary, and its B_max was 1.33 fmol/mg tissue and the K_d was 0.357 nM. These results suggest that DA has a direct stimulatory effect on P₄ secretion in PMSG-treated rat ovarian cells through they D₁ receptor. The observed action may indicate a physiological role for DA in the regulation of ovarian functions in rats.

Inhibition by amphetamine of testosterone secretion through a mechanism involving an increase of cyclic AMP production in rat testes

“…However, it is clear that, in addition, the catecholamines can have a direct effect on steroidogenesis at the gonadal level. In the ovaries of immature chicks and immature pregnant-mare serum treated rats, isoprenaline (a ,B-adrenoceptor agonist) increases progesterone accumulation Mori et al, 1994), and in women with polycystic ovarian syndrome excess ovarian noradrenaline correlated with a hyperandrogenaemic status (Yoshino et al, 1991). In the immature golden hamster testes, noradrenaline, adrenaline, isoprenaline and phenylephrine (an a-adrenoceptor agonist) all significantly stimulate testosterone production in vitro and the effect of noradrenaline can be blocked by both ,B-and a-receptor antagonists (Mayerhofer et al, 1992).…”

Effect of feeding fermented rice punch on oestrous induction in anoestrous bitches

“…Vomiting is a frequently observed side effect (3–25 per cent of cases) within one hour after the first treatment with bromocriptine or cabergoline ( Arbeiter and others 1988 , Jochle and others 1989 , Verstegen and others 1999 ). In rats, dopamine agonists and antagonists affect ovarian steroidogenesis ( Mori and others 1994 ). Inspired by this point in the mouse germ (Malt) fed a control object, and the concentration of prolactin in mice decreases after they giving birth ( Song and others 1994 ).…”

Using haplotype probabilities in categorical survival analysis: a case study with three candidate genes in an Iberian × Meishan F2 population of newborn piglets

“…Note that DBH is an enzyme of the catecholamine biosynthetic pathway that catalyses the hydrolysis of dopamine to norepinephrine. Catecholamines play an essential role in mammalian development and metabolism and DBH has been related to ovarian development and mature gonadal function (Mori et al. 1994; Mayerhofer et al.…”