细胞外腺苷5'-三磷酸(ATP)是最著名和经常研究的神经递质之一。其广谱的生物活性受嘌呤能受体激活的制约,包括P2X2受体。P2X2受体存在于许多物种的中枢和外周神经系统中,包括实验动物,家畜,和灵长类动物。然而,P2X2受体在家猪神经系统中的分布,一个越来越多用作实验模型的物种,至今未知。因此,这项研究旨在确定P2X2受体在猪小肠(十二指肠,空肠,和回肠)通过免疫荧光法。此外,通过确定所选神经肽的共存性来分析猪小肠的P2X2免疫反应性(IR)ENS神经元的化学代码,即,血管活性肠多肽(VIP),P物质(sP),还有Galanin.P2X2-IR神经元存在于肌间神经丛(MP)中,外粘膜下神经丛(OSP),和小肠(十二指肠,空肠,和回肠)。从44.78±2.24%(十二指肠)到63.74±2.67%(回肠)的MP神经元为P2X2-IR。OSP的相应范围为44.84±1.43%(十二指肠)至53.53±1.21%(空肠),在ISP中,从53.10±0.97%(十二指肠)到60.57±2.24%(回肠)。免疫荧光染色显示MP中存在P2X2-IR/甘丙肽-IR和P2X2-IR/VIP-IR神经元,OSP,和小肠切片的ISP。在ENS中测试的任何神经节的P2X2-IR神经元中未检测到sP的存在。我们的结果首次表明P2X2受体存在于MP中,ISP,猪所有小肠段的OSP神经元,这可能表明它的激活会影响小肠的作用。此外,P2X2受体与甘丙肽或VIP之间可能存在功能性相互作用,但不是SP,在猪小肠的ENS中。
Extracellular adenosine 5\'-triphosphate (ATP) is one of the best-known and frequently studied neurotransmitters. Its broad spectrum of biological activity is conditioned by the activation of purinergic receptors, including the
P2X2 receptor. The
P2X2 receptor is present in the central and peripheral nervous system of many species, including laboratory animals, domestic animals, and primates. However, the distribution of the P2X2 receptor in the nervous system of the domestic pig, a species increasingly used as an experimental model, is as yet unknown. Therefore, this study aimed to determine the presence of the P2X2 receptor in the neurons of the enteric nervous system (ENS) of the pig small intestine (duodenum, jejunum, and ileum) by the immunofluorescence method. In addition, the chemical code of P2X2-immunoreactive (IR) ENS neurons of the porcine small intestine was analysed by determining the coexistence of selected neuropeptides, i.e., vasoactive intestinal polypeptide (VIP), substance P (sP), and galanin. P2X2-IR neurons were present in the myenteric plexus (MP), outer submucosal plexus (OSP), and inner submucosal plexus (ISP) of all sections of the small intestine (duodenum, jejunum, and ileum). From 44.78 ± 2.24% (duodenum) to 63.74 ± 2.67% (ileum) of MP neurons were
P2X2-IR. The corresponding ranges in the OSP ranged from 44.84 ± 1.43% (in the duodenum) to 53.53 ± 1.21% (in the jejunum), and in the ISP, from 53.10 ± 0.97% (duodenum) to 60.57 ± 2.24% (ileum). Immunofluorescence staining revealed the presence of
P2X2-IR/galanin-IR and
P2X2-IR/VIP-IR neurons in the MP, OSP, and ISP of the sections of the small intestine. The presence of sP was not detected in the
P2X2-IR neurons of any ganglia tested in the ENS. Our results indicate for the first time that the P2X2 receptor is present in the MP, ISP, and OSP neurons of all small intestinal segments in pigs, which may suggest that its activation influences the action of the small intestine. Moreover, there is a likely functional interaction between P2X2 receptors and galanin or VIP, but not sP, in the ENS of the porcine small intestine.