FETAL SWALLOWING--ONTOGENY AND REGULATION

口渴和吞咽是一种基本的生物系统 调节体内水分动态平衡。宫内吞咽，由 胎儿的“口渴”和大脑皮层状态，会导致 羊水、电解质和内分泌因素。在.期间 围产期、激素印迹和生理因素的调节 口渴可能会永久性地改变成人的液体平衡。因此，对其进行研究。 胎儿“口渴”和吞咽有助于理解 流体调节机制的发展。此外，还分析了 食管液流动模式和胎儿行为状态可能提供 洞察新生儿口渴、反流和异常的关系 呼吸模式。自发性和口渴调节的吞咽行为 在羊和人体内发育和成熟。因此，胎儿模型是 有必要研究口渴调节的个体发生。我们有 建立绵羊胎儿慢性吞咽模型 活动性和体积与胎儿行为的同步测定 州政府。我们已经证明，类似于成人，胎儿吞咽 这两种情况都是自发发生的，都可以被引发糖尿病的因素刺激。 然而，胎儿对已知的糖尿病刺激的反应可能不同于 成年人。此外，自发的胎儿吞咽活动可能会受到抑制。 根据行为状态的改变。这个项目将 描述自发性胎儿吞咽的个体发育，存在 昼夜节律及其与胎儿行为状态成熟的关系。 初级全身刺激对胎儿吞咽刺激的个体发育 (高渗与血管紧张素II；AII)与精氨酸的调节 将对加压素(AVP)和心钠素(ANF)进行研究。这个 AII和AVP刺激吞咽的受体介导将被探讨 选择性受体拮抗剂。此外，中枢刺激和 主要内分泌因子(AII、AVP、ANF)抑制吞咽 被探索。绵羊模型提供了研究的机会，在一个 早熟物种，“口渴”生理学的个体发育，一个重要的 相对未被开发的围产期生理学领域。

Thirst and swallowing represent a fundamental biologic system for the regulation of body water homeostasis. In-utero swallowing, modulated by fetal "thirst" and electrocortical state, results in the resorption of amniotic fluid water, electrolytes and endocrine factors. During the perinatal period, imprinting of hormonal and physiologic factors regulating thirst may permanently alter adult fluid balance. Therefore, the study of fetal "thirst" and swallowing can contribute to an understanding of the development of mechanisms for fluid regulation. In addition, analysis of patterns of esophageal fluid flow and fetal behavioral states may provide insight into the association of neonatal thirst, regurgitation and altered breathing patterns. Spontaneous and thirst-mediated swallowing behavior develop and mature in-utero in sheep and humans. Thus, a fetal model is necessary to investigate the ontogenesis of thirst regulation. We have developed a chronic ovine fetal model for the quantification of swallowing activity and volume and the simultaneous determination of fetal behavioral state. We have demonstrated that, similar to the adult, fetal swallowing both occurs spontaneously and can be stimulated by dipsogenic factors. However, fetal responses to known dipsogenic stimuli may differ from the adult. Furthermore, spontaneous fetal swallowing activity may be suppressed in accordance with behavioral state alterations. This project will characterize the ontogeny of spontaneous fetal swallowing, the presence of diurnal rhythms and the association with fetal behavioral state maturation. The ontogeny of fetal swallowing stimulation by primary systemic stimuli (hyperosmolality and angiotensin II; AII) and the modulation by arginine vasopressin (AVP) and atrial natriuretic factor (ANF) will be studied. The receptor mediation of AII and AVP stimulated swallowing will be probed with selective receptor antagonists. In addition, the central stimulation and suppression of swallowing by primary endocrine factors (AII, AVP, ANF) will be explored. The ovine model offers the opportunity to study, in a precocial species, the ontogeny of "thirst" physiology, an important but relatively unexplored area of perinatal physiology.