RESPIRATORY FACTORS IN BLOOD PRESSURE REGULATION

流行病学研究表明，行为压力可以参与 在原发性高血压的发展过程中，但介体 生理机制尚待阐明。来自我们的研究 实验室已经支持了高血压可以 发展为高钠摄入量和厌食性之间的交互作用 抑制呼吸活动的行为调节程序。 其机制可能与二氧化碳分压、肾钠氢比值升高有关。 交换、肾脏钠滞留、内源性洋地黄样刺激 钠泵抑制剂(EDLF)及其对钠泵活性的抑制作用 血管平滑肌，导致血管内钠和钙的增加， 以及在增加的背景下增加的总外周阻力 血浆体积。 本年度静息潮气末二氧化碳(PETCO2)的稳定性 血压正常的受试者，其与人格因素的关系， 以及高钠摄入量对静息和运动的不同影响 青年(40岁以下)和老年(40岁以上)动态血压 40)研究了人体作为个体静息PETCO2的函数。 研究发现，静息的PETCO2在六个月内相对稳定， 在新神经质量表得分较高的受试者中得分最高 (它评估负面情绪状态的体验)。高膳食 钠摄入量与夜间尿钠排泄增加相关 并增加了所有受试者的体重，无论PETCO2状态如何。 在老年人中，较高的静息PETCO2与 包括静息血压和24小时血压。在年轻人中，高钠 摄入量在24小时内增加，但不是休息时的血压。血浆EDLF 静息PETCO2较高的受试者，无论是在静息前后，都是更高的 钠负荷，表明钠敏感受试者血浆容量增加。 这是首次将PETCO2确定为钠的危险因素的研究 敏感性，并开辟了一个新的研究领域的起源 静息PETCO2的个体差异。

Epidemiological studies indicate that behavioral stresses can participate in the development of primary hypertension, but the mediating physiological mechanisms remain to be clarified. Studies from our laboratory have provided support for the view that hypertension can develop as an interaction between high sodium intake and aversive behavioral conditioning procedures that suppress respiratory activity. The mechanism is hypothesized to involve increases in pCO2, renal Na/H exchange, renal Na retention, stimulation of endogenous digitalis-like sodium pump inhibitors (EDLF) and inhibition of Na pump activity in vascular smooth muscle, leading to increases in intravascular Na and Ca, and increased total peripheral resistance in a context of increased plasma volume. During the current year, stability of resting end tidal CO2 (PETCO2) in normotensive human subjects, its associations with personality factors, and the differential effects of high dietary sodium intake on resting and ambulatory blood pressure of younger (below age 40) and older (above age 40) humans as a function of individual resting PETCO2 were investigated. Resting PETCO2 was found to be relatively stable over a six month period, and to be highest in subjects who were high on the NEO Neuroticism Scale (which assesses experience of negative emotional states). High dietary Na intake was associated with increased overnight urinary Na excretion and increased body weight in all subjects, regardless of PETCO2 status. In older adults, higher resting PETCO2 was associated with increases in both resting and 24-hour blood pressure. In younger adults, high Na intake increased 24-hour, but not resting, blood pressure. Plasma EDLF was higher in subjects with higher resting PETCO2, both before and after Na loading, indicating increased plasma volume in Na sensitive subjects. These are the first studies to identify PETCO2 as a risk factor for Na sensitivity, and open a new area of investigation of the origins of individual differences in resting PETCO2.