Lambert G W, Eisenhofer G, Esler M D
Human Autonomic Function Laboratory, Baker Medical Research Institute, Prahran, Vic, Australia.
Psychoneuroendocrinology. 1994;19(1):33-41. doi: 10.1016/0306-4530(94)90057-4.
Using percutaneously placed arterial and venous catheters, we examined the influence of aging on the plasma concentration, whole body production rate, and renal clearance of homovanillic acid (HVA) in 60 healthy adult volunteers. The arterio-renal fractional extraction of HVA combined with the renal plasma flow (Fick Principle) were used to estimate the whole body HVA production rate and the renal plasma HVA clearance. The arterial HVA plasma concentration, whole body rate of HVA production, and HVA plasma clearance were determined to be 54 +/- 3 nmol/l, 27 +/- 2 nmol/min and 502 +/- 32 ml/min, respectively. The resting arterial HVA plasma concentration was positively correlated with aging, with the increased HVA concentrations in the older subjects being due to a diminished renal HVA plasma clearance. The diminished clearance of HVA occurred in response to a decreased renal plasma flow; the fractional extraction of HVA across the kidney remained unchanged with aging. This study emphasises the need for using age-matched control groups in neurochemical and neuropsychiatric studies, and demonstrates that increases in the arterial level of HVA do not necessarily reflect an increased rate of HVA production but may arise due to a diminished excretion rate of HVA from the body.
我们使用经皮放置的动脉和静脉导管，研究了衰老对60名健康成年志愿者血浆中高香草酸（HVA）浓度、全身生成率及肾脏清除率的影响。结合肾血浆流量（菲克原理）的HVA动 - 肾分数提取用于估计全身HVA生成率和肾血浆HVA清除率。动脉血HVA血浆浓度、全身HVA生成率和HVA血浆清除率分别测定为54±3 nmol/l、27±2 nmol/min和502±32 ml/min。静息动脉血HVA血浆浓度与衰老呈正相关，老年受试者中HVA浓度升高是由于肾血浆HVA清除率降低所致。HVA清除率降低是由于肾血浆流量减少；随着衰老，HVA在肾脏的分数提取保持不变。本研究强调在神经化学和神经精神病学研究中使用年龄匹配对照组的必要性，并表明动脉血HVA水平升高不一定反映HVA生成率增加，而可能是由于体内HVA排泄率降低所致。
