Kisspeptin-10对鹌鹑开产及胆固醇代谢的影响

Effects of kisspeptin-10 on the onset of egg laying and cholesterol metabolism in quails

为了探索kisspeptin-10(Kp-10)对禽类产蛋启动和脂代谢的影响,将75羽22日龄雌鹌鹑随机分为3组:腹腔注射300μL生理盐水组(对照组,C),注射0.1 nmol Kp-10(低剂量组,L)和1 nmol Kp-10组(高剂量组,H),每日注射1次,连续注射3周。记录鹌鹑开产情况并于60日龄时采集血液和肝脏组织,检测血清中雌二醇(E2),血清和肝脏中总胆固醇(Tch)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的含量,以及肝脏胆固醇代谢相关因子mRNA和蛋白水平。结果表明:与对照组相比,L组和H组鹌鹑开产率分别显著和极显著提高(P<0.05和P<0.01);注射Kp-10增加血液E2浓度且于高剂量时达显著水平;H组鹌鹑血清Tch和HDL-C浓度显著降低,肝脏Tch显著升高;L组血液和肝脏HDL-C浓度显著降低;H组鹌鹑肝脏中胆固醇7α-羟化酶(CYP7A1)mRNA转录极显著增加,而3-羟-3-甲基戊二酸单酰CoA还原酶(HMGCR)mRNA、固醇调节元件结合蛋白(SREBP-2)mRNA转录和蛋白表达均无显著性差异(P>0.05)。结论:产蛋前注射Kp-10可显著提高鹌鹑开产率,增加雌激素分泌水平,增强肝脏合成胆固醇的能力。

In order to investigate the effect of kisspeptin-10（Kp-10）on the onset of egg laying and lipids metabolism in birds,75 female quails（22 days of age）were subjected to 0（control,C）,0.1 nmol（low dosage,L group）and 1.0 nmol（high dosage,H group）Kp-10 administration by intraperitoneal injection daily.The experimental time has lasted for 21 days.Kp-10 was disolved in saline and the total volume for injection was 300 μL.The information of egg laying was recorded daily.At 60 days of age,quails were sacrificed and samples including serum and liver were collected for analysis.The concentration of estrogen（E2）in serum and cholesterol metabolism related genes expression in liver,were measured respectively.The results showed that Kp-10 treatment under low as well as high dosage significantly increased the egg laying rate and advanced the onset of egg laying of quails（P0.05）.Serum E2 concentration was increased by Kp-10 treatment on dose dependent manner and reached the statistically significance in H group of quails（P0.05）.Compared with the control group,the concentration of total cholesterol（Tch）and high density lipoprotein cholesterol（HDL-C）in serum of quails in H group significantly decreased（P0.05）,however,the level of Tch in liver showed a significant increase in H group（P0.05）.Real-time RT-PCR results showed that cholesterol-7alpha-hydroxylase（CYP7A1）gene transcription in liver was significantly up-regulated by high but not low dosage of Kp-10 treatment（P0.01）.The gene expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase（HMGCR）was increased by Kp-10 treatment but did not reach the statistical significance（P0.05）.In addition,compared to the control group,there was no significant change of sterol regulatory element-binding protein 2（SREBP-2）mRNA transcription or protein expression in liver of quails（P0.05）.These results indicated that exogenous kisspeptin injection can advance egg laying onset rate of quails and increase lipogenesis in liver.