BLOOD PRESSURE REGULATION DURING PREGNANCY

描述：压力感受器反射功能在 包括类固醇激素在内的几个因素的影响。在……里面 怀孕时，压力感受器反射会减弱 在怀孕后期，动物无法维持压力 在大出血期间。因为出血在分娩中是很常见的 和交付，理解这一观察的重要性是 值得注意的是。当前提案中要检验的假设 这种缺陷发生在大脑或大脑的传出部分 反射通路不变，传入通路不变。有意识的 将对兔子进行研究，以确定交感神经活动是否 在出血期间怀孕的动物体内较少。对同情的评估 活动包括，肾神经记录和局部阻力， 血浆儿茶酚胺、总和肾脏去甲肾上腺素溢出，以及 肾上腺和神经节酪氨酸羟基酶的mRNA水平。 单一动脉压力感受器纤维和传出纤维的反应性 对刺激降主动脉降压神经的反应将是 下定决心。分离阻力血管的血管扩张剂反应 也要接受评估。孕期和孕期上述变化的时间 将对哺乳期进行研究。

DESCRIPTION: Baroreceptor reflex functioning is under the influence of several factors including steroid hormones. In pregnancy, there is an attenuation of the baroreceptor reflex such that in late pregnancy, animals are unable to maintain pressure during hemorrhage. Since hemorrhage is a common occurrence in labor and delivery, the importance of understanding this observation is noteworthy. The hypothesis to be tested in the current proposal is that this deficit occurs in the brain or efferent part of the reflex pathway whereas the afferent pathway is not altered. Conscious rabbits will be studied to determine if sympathetic activity is less in pregnant animals during hemorrhage. Assessments of sympathetic activity include, renal nerve recordings and regional resistances, plasma catecholamines, total and renal norepinephrine spillover, and adrenal and ganglionic levels of tyrosine hydroxylase mRNA. Responsiveness of single arterial baroreceptor fibers and efferent responses to stimulation of the aortic depressor nerve will be determined. Vasodilator responses of isolated resistance vessels will also be assessed. The timing of the above changes during pregnancy and lactation will be studied.