Presynaptic alpha-receptor subsensitivity after long-term antidepressant treatment.
Presynaptic alpha-receptor subsensitivity after long-term antidepressant treatment.
复制标题
长期抗抑郁治疗后突触前α受体不敏感。
作者：
F. Crews;C. Smith
大鼠每日2次给予地昔帕明3周后，场刺激左心房肌条肾上腺素能神经元的频率-反应曲线明显左移，[~ 3 H]去甲肾上腺素的外排明显增强。给药1天后，频率-反应曲线仅有轻微偏移，[3 H]去甲肾上腺素流出量也略有增加，尽管[3 H]去甲肾上腺素摄取的抑制作用已经达到最大，而酚苄明导致频率-反应曲线进一步向左偏移，与单独地昔帕明治疗3周后发生的情况相似。突触前α受体敏感性的逐渐降低可以解释三环类抗抑郁药临床作用延迟的原因。
After 3 weeks of twice-daily administration of desipramine to rats, the frequency-response curve for field stimulation of adrenergic neurons in isolated left atrial strips was shifted markedly to the left and the efflux of [3H]norepinephrine was enhanced greatly. After 1 day of treatment, only slight shifts in the frequency-response curve and small increases in [3H]norepinephrine efflux occurred although inhibition of [3H]norepinephrine uptake was already maximal, and phenoxybenzamine caused a further shift to the left in the frequency-response curve similar to that which occurred after 3 weeks of desipramine treatment alone. A gradual decrease in the sensitivity of the presynaptic alpha receptor would explain the delay in the onset of the linical effect of the tricyclic antidepressants.