【摘要】 观察了6名19～21岁男性健康受试者,头低位-6°卧床8天生理生化指标昼夜节律特性的变化。结果:心输出量、脉压和去甲肾上腺素日平均水平显著下降;外周阻力、尿中的Na~+、K~+和皮质醇含量显著增加。这表明,卧床使心血管功能减弱,交感神经兴奋性下降,水盐代谢紊乱。从心输出量和去甲肾上腺素之间的中度正相关关系,可以推测去甲肾上腺素对卧床期心输出量的调节可能起着重要作用。更多还原

【Abstract】 Six healthy male volunteers aged 19—21 were selected as test subjects. The schedule of experiments included a 3—day control period ( pre—HDT), a 8—day bed rest period with head down tilt of —6°(HDT—6°) and a 5—day recovery period (post—HDT). Physiological parameters (SV, CO,HR, BP, TFI, EVI, LVET) were measured four times and norepinephrine (NE), epinephrine (E), potassium (K~+), sodium (Na~+) and cortisol excretion in urine were assayed six times daily in the experiment. The results indicated that SV, CO, pulse pressure and NE excretion decreased significantly and peripheral resistance, K~+, Na~+ and cortisol excretions increased markedly during HDT—6°. Circadian rhythmic changes of the cardiovascular and biochemical parameters were also observed. The fact that there was a positive correlation with medium significance between cardiac output and NE reflects that NE might play an important role in the control of CO during bed rest.更多还原