OPIOIDS INDUCE POSTURAL ASYMMETRY IN SPINAL RAT - THE SIDE OF THE FLEXED LIMB DEPENDS UPON THE TYPE OF OPIOID AGONIST
OPIOIDS INDUCE POSTURAL ASYMMETRY IN SPINAL RAT - THE SIDE OF THE FLEXED LIMB DEPENDS UPON THE TYPE OF OPIOID AGONIST
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DOI：
10.1016/0006-8993(89)90193-5
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发表时间：
1989-02-20
期刊：
影响因子：
2.9
通讯作者：
KOBYLYANSKY, AG
中科院分区：
文献类型：
--
作者：
BAKALKIN, GY;KOBYLYANSKY, AG
蛛网膜下腔注射κ受体激动剂布马佐辛和强啡肽（1-13）、σ受体激动剂SKF 10.047以及σ受体激动剂[d-Ala 2，[d-Ala 2，d-Leu 5]-脑啡肽（DADL）和Met-脑啡肽，但不注射μ受体激动剂吗啡，可引起大鼠后肢姿势不对称。目视记录不对称。如果腿在动物纵轴上的投影小于其对应物上的投影，则认为腿弯曲。屈曲腿的一侧取决于药物的类型：布马佐辛、强啡肽（1-13）和甲硫氨酸脑啡肽主要诱导右腿屈曲，SKF 10.047诱导左腿屈曲（在某些剂量下，没有侧偏好），而在DADL的情况下，屈曲腿的一侧取决于药物的剂量。对称的二头肌和股四头肌的肌电图活动的比较显示，布马佐辛相当有利于右后肢的屈曲反射，而不影响左肢体反射。作为一项规则，弯曲的腿确定视觉表现出较高的肌电图活动的股二头肌相比，对称的。阿片受体拮抗剂纳洛酮显着降低动物的比例与姿势不对称。在某些动物中，不对称的程度和屈曲侧不是恒定的，而是随时间而变化的。然而，每组动物的平均不对称幅度、不对称动物百分比和左/右屈曲比保持恒定。屈曲侧也取决于脊髓横断的水平：在T1-T4和T5-T6水平横断后蛛网膜下注射布马佐辛和甲硫氨酸脑啡肽分别主要诱导右腿和左腿屈曲。在给予布马佐辛的生理学完整动物中，即使后来切断脊髓，也没有发生不对称，即脊髓横断是不对称发生所必需的。这些数据表明，维持后肢肌张力的神经元和对称于矢状面的神经元对κ-、σ-和σ-激动剂具有不同的敏感性。在大多数动物中，对某些激动剂具有较高特异性的神经元位于矢状面的一侧。
The κ-agonists bremazocine and dynorphin (1–13), the σ-agonist SKF 10.047 as well as the σ-agonists [d-Ala2, [d-Ala2,d-Leu5]-enkephalin (DADL) and Met-enkephalin, but not the μ-agonist morphine, applied subarachnoidally to the could portion of the transected spinal cord (at the T3-T4level) induced postural asymmetry of the hind limbs in rats. Asymmetry was registered visually. The leg was regarded as flexed if its projection on the longitudinal axis of the animal was smaller than that on its counterpart. The side of the flexed leg depended upon the type of drug: bremazocine, dynorphin(1–13) and Met-enkephalin predominantly induced flexion of the right leg, SKF 10.047 induced flexion of the left leg (at some doses there is no side preference), while in the case of DADL the side of the flexed leg depended upon the dose of the drug. Comparison of electromyographic activity of the symmetric biceps and quadriceps femoris revealed that bremazocine considerably facilitates the flexion reflex of the right hind limb without affecting the left limb reflex. As a rule, a flexed leg determined visually exhibited higher EMG activity of the biceps femoris as compared with a symmetric one. The opiate antagonist naloxone significantly reduced the percentage of animals with postural asymmetry. The magnitude of asymmetry and the side of flexion were not constant in some animals, but changed with time. However, the mean magnitude of asymmetry, the percentage of animals with asymmetry and the left/right flexion ratio in each group of animals remained constant. The side of flexion also depended upon the level of spinal cord transection: bremazocine and Met-enkephalin injected subarachnoidally following transection at the T1-T4and T5-T6levels predominantly induced flexion of the right and the left leg, respectively. Asymmetry did not develop in physiologically intact animals given bremazocine, even if the spinal cord was cut later, i.e. transection of the spinal cord was necessary for the development of asymmetry. These data indicate that the neurons which maintain muscular tone of the hind limbs and which are located symmetrically to the sagittal plane, have different sensitivities to κ-, σ-, and σ-agonists. In most animals, neurons with a higher specificity to some agonist are localized on one side of the sagittal plane.