PANCREATIC POLYPEPTIDE--CENTRAL DIGESTION CONTROL

胰多肽[PP]是由胰腺内分泌细胞释放的 在进食之后。从胰腺释放这种多肽：， 导致胰腺外分泌减少，以及改变 在胃肠道分泌和运动方面。PP对消化的作用有 很难解释，因为它对消化功能有急性作用 不是直接的。PP需要完整的迷走神经传出神经 效应，这一事实导致推测PP可能控制迷走神经传出 通过脑干的内分泌作用投射到肠道和胰腺 结构。这一观点最近得到了显著的加强，因为 发现延髓中的迷走神经背侧复合体含有较高的 PP的可饱和受体和特异性受体的浓度。因此，胰腺 多肽[PP]可能代表一种独特的消化内分泌反馈 直接调节迷走神经兴奋性的控制信号 控制消化功能的反射回路。 我们计划使用两种不同的方法来直接检验这一假设。 首先，我们将PP直接应用于迷走神经背侧复合体，使用 定量微压注射技术。这将确定PP是否 可以通过迷走神经反射回路产生可测量的变化 胃肠和/或胰腺功能。研究将在以下地点进行 麻醉和急性清醒准备。 接下来，我们将确定PP是如何影响神经生理功能的 脑干迷走-迷走神经回路神经元成分的鉴定 完好无损的麻醉大鼠。这些研究将确定PP如何作用于 消化控制反射的单个可识别神经元成分。 总而言之，这些研究将提供一个迹象，说明这种独特的 胰腺内分泌激素可通过以下途径控制一系列消化功能 作用于脑干的迷走神经回路。

Pancreatic polypeptide [PP] is released from pancreatic endocrine cells following feeding. The release of this peptide from the pancreas:, produces a reduction in pancreatic exocrine secretion, as well as changes in gastrointestinal secretion and motility. PP action on digestion has been difficult to explain in that its acute actions on digestive functions are not direct. Intact vagal efferent innervation is required for PP effects, a fact that lead to speculation that PP may control vagal efferent projections to the gut and pancreas through endocrine action on brainstem structures. This view recently received significant reinforcement with the finding that the dorsal vagal complex in the medulla contains a high concentration of saturable and specific receptors for PP. Thus, pancreatic polypeptide [PP] may represent a unique digestive endocrine feedback control signal which directly regulates the excitability of vago-vagal reflex circuits to control digestive functions. We plan to apply two separate methods to test this hypothesis directly. First, we will apply PP directly to the dorsal vagal complex using quantitative micropressure injection techniques. This will establish if PP can act via vago-vagal reflex circuits to produce measurable changes in gastrointestinal and/or pancreatic functions. Studies will be performed in both anesthetized and acute, awake preparations. Next, we will determine how PP affects the function of neurophysiologically identified neuronal components of vago-vagal circuits in the brainstem in the intact, anesthetized rat. These studies will determine how PP acts on individual identifiable neuronal components of digestion control reflexes. Together, these studies will provide an indication of how this unique pancreatic endocrine hormone can control an array of digestive functions by acting on vagal circuits in the brainstem.