褪黑素受体MT1和MT2在绵羊胃中的分布及表达

【目的】应用分子生物学技术探究绵羊不同胃室组织褪黑素(MT)特异性膜受体MT1和MT2的分布规律及表达模式,以初步探明绵羊不同胃室组织褪黑素调节胃消化的生物效应机制。【方法】采集绵羊瘤胃背囊、瘤胃腹囊、网胃、瓣胃和皱胃5个组织部位,用ELISA、实时荧光定量PCR、免疫组化和Western blotting方法检测褪黑素特异性膜受体MT1和MT2在绵羊胃组织不同部位的分布规律及表达模式。【结果】ELISA结果显示,绵羊各胃组织中均含有褪黑素,且皱胃中褪黑素含量最高,瓣胃次之,瘤胃背囊、瘤胃腹囊和网胃中均较低。实时荧光定量PCR结果显示,MT1和MT2基因mRNA在皱胃中含量均最高,其次是瘤胃腹囊,在瘤胃背囊和网胃中含量较低。免疫组化结果显示,MT1和MT2蛋白在绵羊各胃组织中均有分布,主要表达于各胃组织的黏膜层,且在皱胃腺体中的分布呈从底部到颈部逐渐增多的趋势。Western blotting结果显示,MT1和MT2蛋白在网胃中表达均最高,瓣胃次之,在瘤胃背囊、瘤胃腹囊和皱胃中表达均较低。【结论】褪黑素在绵羊各胃组织中差异化表达从而发挥多样性生理功能,可能通过与胃组织上特异性受体MT1和MT2结合,通过信号传导系统而调控前胃受食糜刺激后发生反刍生理过程。

Distribution and Expression of Melatonin Receptors MT1 and MT2 in Various Stomach Tissues of Sheep

【Objective】 This study was aimed to detect the distribution and expression of melatonin (MT) specific membrane receptors MT1 and MT2 in different parts of sheep gastric tissues by traditional molecular biological methods to preliminarily explore and clarify the difference of melatonin concentration and action mode in these areas.【Method】 The methods of ELISA, Real-time PCR, immunohistochemistry and Western blotting were used to detect the distribution and expression of melatonin specific membrane receptors MT1 and MT2 in sheep saccus ruminis dorslis, saccus ruminis ventralis, reticulum, omasum and abomasum.【Result】 The results of ELISA showed that melatonin was contained in all gastric tissues of sheep, and the content of melatonin in abomasum was the highest, followed by omasum, and that in saccus ruminis dorslis, saccus ruminis ventralis and reticulum were lower. The results of Real-time PCR showed that the contents of MT1 and MT2 genes mRNA were the highest in the abomasum, followed by saccus ruminis ventralis, and lower in saccus ruminis dorslis and reticulum. Immunohistochemistry results showed that MT1 and MT2 proteins were distributed in all gastric tissues of sheep, mainly expressed in the mucosal layer of each gastric tissue, and the distribution of MT1 and MT2 proteins gradually increased from the bottom to the neck in the abomasum glands. The results of Western blotting showed that the expression of MT1 and MT2 proteins was the highest in reticulum, followed by omasum, and lower in saccus ruminis dorslis, saccus ruminis ventralis and abomasum.【Conclusion】 Melatonin was differentially expressed in various gastric tissues of sheep so as to play a variety of physiological functions. It might regulate the physiological process of rumination after chyme stimulation through the signal transduction system by combining with the specific receptors MT1 and MT2 in gastric tissues.