Baxter L R, Kelly R C, Peter J B, Liston E H, Touserkani S
Department of Psychiatry and Biobehavioral Science, UCLA School of Medicine 90024.
J Psychiatr Res. 1988;22(2):131-9. doi: 10.1016/0022-3956(88)90077-5.
Phenylacetate (PAA) is the metabolic end-product of phenylalanine, a catecholamine precursor, and of phenylethylamine, a centrally active neurochemical substance which has been implicated in the actions of stimulant medications. PAA has been reported to be low in unipolar depression. We measured 24-h urinary PAA in normal controls (N = 21) and in-patients with unipolar depression (N = 33; 12 drug-free) and did subsequent dexamethasome suppression tests (DST). We also gave patients methylphenidate challenges, examining mood response. There were no significant differences between depressed patients and controls in 24-h urinary PAA excretion (P greater than 0.9). However, the variance in PAA excretion was higher in patients than normals and 5 patients had values at or above the 99% confidence limits for the normal control group. There was no association of DST results with PAA excretion (P greater than 0.4). Patients with a worsened mood after taking methylphenidate excreted less PAA than those with an improved mood, however (P less than 0.025). The clinical and theoretical significance of these results is discussed.
苯乙酸（PAA）是苯丙氨酸（一种儿茶酚胺前体）以及苯乙胺（一种具有中枢活性的神经化学物质，与刺激性药物的作用有关）的代谢终产物。据报道，PAA在单相抑郁症患者中含量较低。我们测量了21名正常对照者和33名单相抑郁症住院患者（其中12名未服用药物）24小时尿中PAA的含量，并随后进行了地塞米松抑制试验（DST）。我们还对患者进行了哌醋甲酯激发试验，观察情绪反应。抑郁症患者和对照者24小时尿中PAA排泄量无显著差异（P>0.9）。然而，患者PAA排泄量的方差高于正常人，有5名患者的值处于或高于正常对照组的99%置信限。DST结果与PAA排泄量无相关性（P>0.4）。不过，服用哌醋甲酯后情绪恶化的患者比情绪改善的患者排泄的PAA更少（P<0.025）。本文讨论了这些结果的临床和理论意义。
