CARDIAC RECEPTOR ACTIVITY IN THE PREGNANT RAT

怀孕大鼠的心脏受体活性

• 批准号: 6888276
• 负责人: MARY Christina HINES
• 金额: $ 21.19万
• 依托单位: UNIVERSITY OF MISSOURI KANSAS CITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6888276
• 关键词: atrium; autonomic reflex; baroreceptors; blood volume; endothelin; female; heart dimension /size; heart electrical activity; heart rate; hemodynamics; intracardiac pressure; laboratory rat; mechanical stress; neuroregulation; nitric oxide; pregnancy circulation; receptor expression; receptor sensitivity; stretch receptors; stretch reflex; sympathetic nervous system; vascular resistance; vasomotion

Increased blood volume and decreased blood pressure are early and sustained alterations of pregnancy that are directly correlated with positive outcomes. The chronic maintenance of these cardiovascular adjustments implies a significant change in autonomic regulatory pathways, and it is known that reflex effects mediated by these pathways are attenuated during rat and human pregnancy, and further blunted during diseases, such as preeclampsia. One of our long-term objectives is to characterize alterations in these neural reflex pathways during pregnancy and to elucidate mechanisms involved. Understanding changes in these cardiovascular regulatory systems will improve clinical management of blood volume and pressure during pregnancy. Using the pregnant rat model, which undergoes hemodynamic changes similar to those in humans, we have demonstrated that afferent discharge in the autonomic receptors, which regulate blood volume and blood pressure, is attenuated during pregnancy. One explanation for a reduction in cardiac receptor sensitivity is the suggestion that pregnancy actually represents an "underfilled" state, and this concept will be explored in the present proposal. In addition, we are investigating the role of alterations in wall stretch and local paracrine factors in the reduction of afferent receptor firing during pregnancy. Based on our findings in the current funding cycle, three aims are proposed for this competing renewal: Aim #1: we will determine if exogenous blood volume expansion restores cardiac receptor activity in the late-pregnant rat to levels observed in the nonpregnant animal, and if volume expansion has a differential effect in the early-pregnant animal; Aim #2: right atrial pressure/dimension relationships will be measured in late-pregnant and nonpregnant animals to gain a better understanding of the degree of stretch "sensed" by cardiac receptors; Aim #3: we will determine whether nitric oxide and/or endothelin, substances known to decrease baroreceptor firing in nonpregnant animals, mediate the reduction in cardiac and baroreceptor activity we have observed during pregnancy. The proposed research plan stems logically from the investigator's currently funded work on alterations in autonomic regulation of cardiovascular function during pregnancy. Data collected during the current grant period have provided intriguing new information about gestational modulation of autonomic receptor activity in the gravid rat. In this competitive renewal we will focus our efforts on mechanisms involved in these changes of pregnancy. The insights gained from these investigations will extend the understanding cardiovascular control in a heretofore-unstudied component of autonomic regulatory pathways in pregnancy, and will further elucidate physiologic as well and pathologic mechanisms of blood volume and blood pressure control during pregnancy that will broaden our knowledge base for clinical management of the pregnant woman.

血容量增加和血压下降是早期和持续的 妊娠的改变与阳性 结果。这些心血管调节的长期维持意味着 自主调节通路的显著变化，并且已知， 在大鼠和人的实验中，由这些途径介导的反射作用减弱， 怀孕期间，并在疾病期间进一步变钝，如先兆子痫。之一 我们的长期目标是描述这些神经反射的变化， 怀孕期间的途径，并阐明有关机制。理解 这些心血管调节系统的变化将改善临床 怀孕期间的血容量和血压管理。利用孕妇 大鼠模型，经历类似于人类的血液动力学变化，我们 已经证明，在自主神经受体， 调节血容量和血压，在怀孕期间衰减。一 心脏受体敏感性降低的解释是， 怀孕实际上代表了一种“未满”的状态， 本提案将探讨这一问题。此外，我们正在调查 室壁伸展和局部旁分泌因子的改变在 怀孕期间传入受体放电减少。根据我们的调查结果 在目前的供资周期中，提出了三个目标， 更新：目标1：我们将确定外源性血容量扩张是否恢复 心脏受体活性在晚孕大鼠中观察到的水平， 非妊娠动物，并且如果体积扩张在 早孕动物;目标2：右心房压力/尺寸关系 将在妊娠晚期和非妊娠动物中进行测量，以获得更好的结果 理解心脏感受器“感知”的伸展程度;目标#3： 我们将确定是否一氧化氮和/或内皮素，已知的物质， 减少非妊娠动物的压力感受器放电，介导 心脏和压力感受器的活动，我们已经观察到在怀孕期间。的 拟议的研究计划从逻辑上源于研究者目前资助的 研究在心脏病发作期间心血管功能自主调节的改变 怀孕在本赠款期间收集的数据提供了 妊娠期自主神经受体调节的有趣新信息 妊娠大鼠中的活性。在这次竞争性的更新中，我们将专注于我们的 努力研究这些妊娠变化的机制。的见解 从这些研究中获得的信息将扩展对心血管疾病的理解， 控制迄今为止尚未研究的自主调节途径的组成部分， 妊娠，并将进一步阐明生理以及病理 怀孕期间的血容量和血压控制机制， 将扩大我们的知识基础，为临床管理的孕妇。

项目成果

Effect of cardiac receptor stimulation on renal vascular resistance in the pregnant rat.

心脏受体刺激对妊娠大鼠肾血管阻力的影响。

• DOI: 10.1152/ajpregu.2000.278.1.r171
• 发表时间: 2000
• 期刊: American journal of physiology. Regulatory, integrative and comparative physiology
• 作者: Hines,T;Herzer,WA
• 通讯作者: Herzer,WA

Pregnancy alters cardiac receptor afferent discharge in rats.

怀孕改变大鼠心脏受体传入放电。

• DOI: 10.1152/ajpregu.2000.278.1.r149
• 发表时间: 2000
• 期刊: American journal of physiology. Regulatory, integrative and comparative physiology
• 作者: Hines,T;Hodgson,TM
• 通讯作者: Hodgson,TM

Baroreceptor afferent discharge in the pregnant rat.

怀孕大鼠的压力感受器传入放电。

• DOI: 10.1152/ajpregu.2000.278.6.r1433
• 发表时间: 2000
• 期刊: American journal of physiology. Regulatory, integrative and comparative physiology
• 作者: Hines,T

The hypo-osmolality of pregnancy does not alter baroreceptor responses to acute changes in osmolality.

妊娠的低渗透压不会改变压力感受器对渗透压急剧变化的反应。

• DOI: 10.1177/1099800405283032
• 发表时间: 2006
• 期刊: Biological research for nursing
• 影响因子: 2.5
• 作者: Hines,Tina;Veeh,Jessica;Grimes,Dawn
• 通讯作者: Grimes,Dawn