Effect of an infusion of free noradrenaline on plasma sulpho-conjugated catecholamine concentration and energy metabolism

本研究的目的是观察输注游离去甲肾上腺素对血浆硫结合儿茶酚胺浓度和能量代谢的影响。6名男性受试者(年龄：24×2岁，最大摄氧量：52.5×5.0ml/kg/min，体脂百分比：11.0×1.2%)。每名受试者均接受0.05µg/kg/min的剂量，连续60分钟。分别于输液前30min、输液中每10min、输液后60min和120min采血，测定血浆中游离和硫酸化儿茶酚胺、游离脂肪酸和甘油。在整个试验过程中，测量过期的空气样本和心率，并在输液期间每10分钟测量一次血压。游离去甲肾上腺素输注后血浆游离去甲肾上腺素和硫酸去甲肾上腺素浓度逐渐升高。血浆肾上腺素浓度无明显影响。氧摄取量、收缩压和舒张压随着去甲肾上腺素剂量的增加而增加。相比之下，输液降低了心率。这些结果表明，1)硫代偶联可能代表了游离儿茶酚胺在释放或注入血液时的失活或储存途径；2)一定剂量的去甲肾上腺素可能是引起能量代谢和脂解的途径。

The purpose of this study was to examine the effect of an infusion of free noradrenaline on plasma sulpho-conjugated catecholamine concentration and energy metabolism. Six male subjects (age : 24*2 yr, maximal oxygen uptake : 52.5*5.0 ml/kg/min, percentage body fat : 11.0*1.2%) participated in this study. Each subject received the dose of 0.05 mug/kg/min for 60 min. Blood samples were drawn at 30 min before infusion, every 10 min during infusion and 60- and 120-min after infusion to analyze for plasma free and sulfated catecholamine, free fatty acid and glycerol. Expired air samples and heart rate were measured throughout the trial, and blood pressure was measured every 10 min during infusion. The infusion of free noradrenaline increased gradually plasma free and sulfated noradrenaline concentrations. Plasma adrenaline concentrations were not significantly affected. Oxygen uptakes, systolic and diastolic blood pressures were increased by noradrenaline dose. In contrast heart rates were decreased by the infusion. These results indicate that 1) sulpho-conjugation could represent an inactivation or storage pathway of free catecholamine when released or infused into blood, and 2) a dose of noradrenaline may be to evoke energy metabolism and lipolysis.