The effects of L-dopa on hypothalamic NPY gene expressions in PCOS model rats

Luteinizing hormone (LH) levels are high in polycystic ovary syndrome(PCOS). Neuropeptide Y(NPY) and Dopaminergic neurons activity are low in this patient. Dopamine increases NPY release. In the present study, the effects of L-dopa and dopamine receptor antagonists were investigated on relative NPY gene expressions in the hypothalamus of PCOS model rats. PCOS condition was induced in fifteen Wistar female rats weighing 180-220g by intramuscular injections of estradiol valerate. ThePCOS rats in three groups received saline, L-dopa (100mg/kg), simultaneous injections of Sulpiride (10mg/kg), SCH23390 hydrochloride (1mg/kg) and Ldopa (100mg/kg) via intraperitoneal injection respectively. Five intact estrous rats as a control group received saline intraperitoneally. Hypothalamic samples were dissected. Mean relativeNPY gene expressions were determinedby real-time polymerase chain reaction (RT-PCR) method. Hypothalamic NPY gene expressions significantly increased in PCOS ratsin comparison to intact ones.L-dopa significantly decreases hypothalamic NPY gene expressions in comparison to PCOS rats. Injections of Ldopa following Sulpiride and SCH23390 did not significantly increase the NPY gene expressions compared to L-dopa group. Increasing the Dopaminergic neurons activity may be useful in the understanding of the infertility mechanism of PCOS via regulating the synthesis of neuropeptides of its neuroendocrine axis

Keywords:

Sulpiride , NPY , L-dopa , SCH23390