Cléroux J, Giannattasio C, Grassi G, Seravalle G, Sampieri L, Cuspidi C, Bolla G, Valsecchi M, Mazzola C, Mancia G
Cattedra di Semeiotica Medica, Università di Milano, Italy.
J Hypertens Suppl. 1988 Dec;6(4):S141-4. doi: 10.1097/00004872-198812040-00041.
This study examined the effects of ageing on the cardiopulmonary receptor regulation of vasomotor tone in skeletal muscle and renin release by the kidney. To this end, the changes in forearm vascular resistance (mean arterial pressure divided by plethysmographically measured forearm blood flow), plasma noradrenaline concentration and plasma renin activity were measured in eight young (23 +/- 2 years, mean +/- s.e.m.) and seven elderly healthy subjects (69 +/- 2 years) during manoeuvres which altered cardiopulmonary receptor activity. The cardiopulmonary receptors were stimulated by increasing central venous pressure through passive leg-raising and deactivated by reducing central venous pressure through non-hypotensive (-15 mmHg) and hypotensive (-40 mmHg) levels of lower body negative pressure. During either manoeuvre, central venous pressure changed by the same amount in both groups, but the reflex changes in forearm vascular resistance, plasma noradrenaline and plasma renin activity were significantly less in elderly subjects. Since the increase in forearm vascular resistance induced by a cold pressor test was comparable in young and elderly subjects, a non-specific depression of cardiovascular responsiveness to neural stimuli can be excluded. Thus, healthy normotensive elderly subjects show an impairment of both vascular and neurohumoral influences exerted by cardiopulmonary receptors. This may be involved in the decreased ability of the elderly to cope with gravity challenges.
本研究探讨了衰老对骨骼肌血管运动张力的心肺受体调节及肾脏肾素释放的影响。为此，在改变心肺受体活性的操作过程中，测量了8名年轻（23±2岁，平均值±标准误）和7名老年健康受试者（69±2岁）的前臂血管阻力（平均动脉压除以体积描记法测量的前臂血流量）、血浆去甲肾上腺素浓度和血浆肾素活性。通过被动抬腿增加中心静脉压刺激心肺受体，通过非低血压（-15 mmHg）和低血压（-40 mmHg）水平的下体负压降低中心静脉压使心肺受体失活。在任何一种操作过程中，两组的中心静脉压变化量相同，但老年受试者前臂血管阻力、血浆去甲肾上腺素和血浆肾素活性的反射性变化明显较小。由于冷加压试验诱导的年轻和老年受试者前臂血管阻力增加相当，因此可以排除对神经刺激的心血管反应性的非特异性抑制。因此，健康的血压正常的老年受试者表现出心肺受体对血管和神经体液影响的损害。这可能与老年人应对重力挑战能力下降有关。
