Expressions of Neuromedin-U and Neuromedin-U Receptor 2 mRNA between Normal and Precocious Puberty Female Rats and Those Significances

Objective To analyze the differences of expressions of neuromedin-U(NMU) and neuromedin U receptor-2(NMUR2) between normal female SD rats and precocious puberty female SD rats,and discuss their effects on the onset of precocious puberty.Methods Sixty female SD rats at 5 days of age were divided into 6 groups randomly:model group 1(precocious prepuberty),model group 2(precocious puberty),model group 3(precocious adult),control group 1(normal prepuberty),control group 2(normal puberty) and control group 3(normal adult),10 rats per group.Model groups were given a single subcutaneous injection of 300 μg danazol to induce true precocious puberty.The expressions of hypothalamic NMUR2 mRNA and pituitary NMU mRNA were assayed by semi-quantitative RT-PCR.Results 1.The expression of NMU mRNA in pituitary were much higher in prepuberty stage(model group 1 and control group 1) than that in puberty(model group 2 and control group 2) and adult stage(model group 3 and control group 3) (Pa0.01),but there were no significant differences between puberty and adult stage(Pa0.05).2.The expression of NMU mRNA in pituitary were much lower in model group 2 than that in control group 1(the same days of age)(P0.01).3.There were no significant difference of NMU mRNA levels between control group 2 and model group 2(P0.05).4.The trend of NMUR2 mRNA levels in hypothalamus were consistent with the NMU mRNA levels in pituitary.Conclusion NMU and NMUR2 may play an important role in the onset of precocious puberty.