Bodnar R J, Glusman M, Brutus M, Spiaggia A, Kelly D D
Physiol Behav. 1979 Jul;23(1):53-62. doi: 10.1016/0031-9384(79)90122-7.
In addition to the well-known activation of the pituitary-adrenal axis, acute exposure to severe stressors includes a temporary analgesia in rats. Thus, the present study investigates whether the pituitary was involved in the mediation of analgesia induced by severe cold-water swim (CWS) stress. Flinch-jump thresholds were measured 30 min following 3.5-min swims in water temperatures ranging from 2-35 degrees C. Compared with untreated normal rats, hypophysectomized rats, receiving corticosterone and thyroxin, displayed significantly less CWS-induced analgesia, while similarly-supplemented normal rats exhibited significantly more CWS-induced analgesia. In a second experiment, operant liminal escape pain thresholds were determined following acute and chronic CWS. Whereas normal rats exhibited profound analgesia following the initial swims, the hypophysectomized rats never displayed any CWS-induced operant escape shifts. Stress-induced alterations in general activity levels and/or thermoregulation were shown to be unrelated to the diminished effectiveness of CNS to produce analgesia in hypophysectomized rats. These data imply that the pituitary is involved in the mediation of CWS-induced analgesia.
除了众所周知的垂体 - 肾上腺轴激活外，大鼠急性暴露于严重应激源还包括暂时的镇痛作用。因此，本研究调查垂体是否参与了由严重冷水游泳（CWS）应激诱导的镇痛作用的介导。在水温为2至35摄氏度的水中游泳3.5分钟后30分钟测量退缩跳跃阈值。与未处理的正常大鼠相比，接受皮质酮和甲状腺素的垂体切除大鼠表现出明显较少的CWS诱导的镇痛作用，而同样补充的正常大鼠表现出明显更多的CWS诱导的镇痛作用。在第二个实验中，在急性和慢性CWS后测定操作性阈下逃避疼痛阈值。正常大鼠在初次游泳后表现出深度镇痛，而垂体切除大鼠从未表现出任何CWS诱导的操作性逃避变化。应激诱导的一般活动水平和/或体温调节的改变被证明与垂体切除大鼠中枢神经系统产生镇痛作用的有效性降低无关。这些数据表明垂体参与了CWS诱导的镇痛作用的介导。
