Kaye W H, George D T, Gwirtsman H E, Jimerson D C, Goldstein D S, Ebert M H, Lake C R
University of Pittsburgh, Western Psychiatric Institute and Clinic, PA 15213.
Psychopharmacol Bull. 1990;26(3):355-9.
Anorexia nervosa is associated with alterations in sympathetic activity and metabolism that persist during and after weight recovery. This study assessed beta-adrenergic receptor activity, an important modulator of vascular and metabolic function, in anorexic patients studied when underweight and at intervals during recovery, in comparison with healthy volunteer women. An increase in heart rate, in response to increasing doses of isoproterenol, served as an index of postsynaptic activity. Anorexic patients, during refeeding and weight gain, needed a significantly higher dose of isoproterenol to increase basal heart rate by 25 beats/minute, compared with underweight anorexic patients. Down-regulated postsynaptic cardiac beta-adrenoceptors during weight gain may protect against refeeding-induced exaggerated sympathetic activity. Because presynaptic beta-adrenoceptors serve as a positive feedback loop for synaptic catecholamine secretion, the increase in plasma norepinephrine concentrations during the isoproterenol infusion served as an index of presynaptic activity. We found that increasing doses of isoproterenol were associated with a linear increase in plasma norepinephrine in each healthy volunteer. In contrast, anorexic patients at any state had a significantly more erratic secretion of plasma norepinephrine in response to increasing doses of isoproterenol. Altered regulation of presynaptic adrenoceptors may explain, in part, the large variance and little consensus between previous studies as to whether anorexic patients have reduced or normal plasma norepinephrine levels.
神经性厌食症与交感神经活动和新陈代谢的改变有关，这些改变在体重恢复期间及之后持续存在。本研究评估了β-肾上腺素能受体活性（血管和代谢功能的重要调节因子），研究对象为体重过轻的厌食症患者以及恢复期间不同阶段的患者，并与健康志愿者女性进行比较。心率随异丙肾上腺素剂量增加而增加，作为突触后活性的指标。与体重过轻的厌食症患者相比，厌食症患者在重新进食和体重增加期间，需要显著更高剂量的异丙肾上腺素才能使基础心率增加25次/分钟。体重增加期间突触后心脏β-肾上腺素能受体下调可能可防止重新进食引起的过度交感神经活动。由于突触前β-肾上腺素能受体作为突触儿茶酚胺分泌的正反馈回路，异丙肾上腺素输注期间血浆去甲肾上腺素浓度的增加作为突触前活性的指标。我们发现，在每位健康志愿者中，异丙肾上腺素剂量增加与血浆去甲肾上腺素呈线性增加有关。相比之下，处于任何状态的厌食症患者对异丙肾上腺素剂量增加的反应中，血浆去甲肾上腺素分泌明显更不稳定。突触前肾上腺素能受体调节改变可能部分解释了先前研究之间关于厌食症患者血浆去甲肾上腺素水平是降低还是正常存在的巨大差异和很少的共识。
