Li Hui, Frisby Claudine L, O'Donnell Tracey A, Kentish Stephen J, Wittert Gary A, Page Amanda J
Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia; South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.
Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia; South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia; Royal Adelaide Hospital, Adelaide, South Australia, Australia.
Peptides. 2015 Sep;71:141-8. doi: 10.1016/j.peptides.2015.07.011. Epub 2015 Jul 21.
Gastric vagal afferents are activated in response to mechanical stimulation, an effect attenuated by neuropeptide W (NPW) in 20-week-old female mice. In this study we aimed to determine whether there were age and sex dependent effects of NPW on gastric vagal afferent mechanosensitivity.
An in vitro gastro-oesophageal preparation was used to determine the effect of NPW on gastric vagal afferent mechanosensitivity from 8 and 20-week-old male and female C57BL/6 mice. Retrograde tracing and laser capture microdissection were used to selectively collect gastric vagal afferent cell bodies. Expression of NPW in the gastric mucosa and its receptor, GPR7, in gastric vagal afferent cell bodies was determined using quantitative RT-PCR.
NPW inhibited gastric tension sensitive vagal afferents from 20-week-old male and female mice, but not 8-week-old mice. In contrast, NPW inhibited the mechanosensitivity of gastric mucosal vagal afferents in 8-week-old male and female mice, but not 20-week-old mice. NPW mRNA expression in the gastric mucosa was higher in 20-week-old male mice compared to 8-week-old male mice. GPR7 mRNA expression in vagal afferent neurons innervating the gastric muscular layers was higher in 20-week-old mice compared to 8-week-old mice in both sexes.
The inhibitory effect of NPW on gastric tension sensitive and mucosal vagal afferents is age but not sex-dependent. These findings suggest that the physiological role of NPW varies depending on the age of the mice.
胃迷走传入神经在受到机械刺激时会被激活，在20周龄雌性小鼠中，神经肽W（NPW）可减弱这种效应。在本研究中，我们旨在确定NPW对胃迷走传入神经机械敏感性是否存在年龄和性别依赖性影响。
使用体外胃食管制备方法来确定NPW对8周龄和20周龄雄性及雌性C57BL/6小鼠胃迷走传入神经机械敏感性的影响。采用逆行追踪和激光捕获显微切割技术选择性收集胃迷走传入神经细胞体。使用定量逆转录聚合酶链反应（RT-PCR）测定胃黏膜中NPW及其受体GPR7在胃迷走传入神经细胞体中的表达。
NPW可抑制20周龄雄性和雌性小鼠的胃张力敏感迷走传入神经，但对8周龄小鼠无效。相反，NPW可抑制8周龄雄性和雌性小鼠胃黏膜迷走传入神经的机械敏感性，但对20周龄小鼠无效。与8周龄雄性小鼠相比，20周龄雄性小鼠胃黏膜中NPW mRNA表达更高。在支配胃肌层的迷走传入神经元中，20周龄小鼠的GPR7 mRNA表达高于8周龄小鼠，且两性均如此。
NPW对胃张力敏感和黏膜迷走传入神经的抑制作用具有年龄依赖性而非性别依赖性。这些发现表明，NPW的生理作用因小鼠年龄而异。
