Zandi Mohammad Reza, Jafarzadeh Shirazi Mohammad Reza, Tamadon Amin, Akhlaghi Amir, Salehi Mohammad Saied, Niazi Ali, Moghadam Ali
Department of Animal Sciences, School of Agriculture, Shiraz University, Shiraz, Iran.
Transgenic Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Int J Mol Cell Med. 2014 Summer;3(3):183-9.
Melanocortin- 4 receptor (MC4R) and agouti- related peptide (AgRP) are involved in energy homeostasis in rats. According to MC4R and AgRP effects on luteinizing hormone (LH) secretion, they may influence the estrous cycle of rats. Therefore, the aim of this study was to investigate the expression of MC4R and AgRP mRNAs at different stages of estrous cycle in the rat's hypothalamus. The estrous cycle stages (proestrus, estrus, metestrus and diestrus) were determined in 20 adult female rats using vaginal smears. The rats were divided into four equal groups (n=5). Four ovariectomized rats were selected as controls two weeks after surgery. Using real- time PCR, relative expressions (compared to controls) of MC4R and AgRP mRNAs in the hypothalamus of rats were compared in four different groups of estrous cycle. The relative expression of MC4R mRNA in the hypothalamus of female rats during proestrus stage was higher than those in other stages (P=0.001). Despite a lower mean of relative expression of AgRP mRNA at proestrus stage, the relative expression of AgRP mRNA of the four stages of estrous cycle did not differ (P>0.05). In conclusion, changes in the relative expression of MC4R and AgRP mRNAs in four stages of rat estrous cycle indicated a stimulatory role of MC4R in the proestrus and preovulatory stages and an inhibitory role of AgRP in gonadotropin releasing hormone (GnRH) and LH secretions.
黑皮质素-4受体（MC4R）和刺鼠相关肽（AgRP）参与大鼠的能量稳态调节。根据MC4R和AgRP对促黄体生成素（LH）分泌的影响，它们可能会影响大鼠的发情周期。因此，本研究旨在探讨大鼠下丘脑发情周期不同阶段MC4R和AgRP mRNA的表达情况。通过阴道涂片法确定了20只成年雌性大鼠的发情周期阶段（动情前期、动情期、动情后期和动情间期）。将大鼠分为四个相等的组（n = 5）。术后两周选择四只去卵巢大鼠作为对照。使用实时PCR，比较了发情周期四个不同组中大鼠下丘脑MC4R和AgRP mRNA的相对表达（与对照相比）。动情前期雌性大鼠下丘脑MC4R mRNA的相对表达高于其他阶段（P = 0.001）。尽管动情前期AgRP mRNA的相对表达平均值较低，但发情周期四个阶段的AgRP mRNA相对表达没有差异（P>0.05）。总之，大鼠发情周期四个阶段MC4R和AgRP mRNA相对表达的变化表明，MC4R在动情前期和排卵前期具有刺激作用，而AgRP对促性腺激素释放激素（GnRH）和LH分泌具有抑制作用。
