Wüllner U, Klockgether T, Schwarz M, Sontag K H
Max-Planck-Institute for Experimental Medicine, Göttingen, F.R.G.
Brain Res. 1987 Sep 29;422(1):129-36. doi: 10.1016/0006-8993(87)90547-6.
Baclofen, an agonist at GABAB receptors injected locally into the rat ventromedial thalamic nucleus (VM) induced catalepsy in a dose-dependent, stereospecific and site-specific way. Baclofen-induced catalepsy was accompanied by tonic activity in the electromyogram (EMG) recorded from the gastrocnemius muscle, which is considered to be a measure of limb rigidity. delta-Aminovalerate (delta-AVA) coadministered with baclofen into the VM prevented the development of both catalepsy and limb rigidity. delta-AVA injected alone into the VM was devoid of depressant or stimulating behavioral effects. In contrast to delta-AVA, bicuculline, a GABAA antagonist, failed to antagonize baclofen-induced catalepsy. On the other hand, catalepsy due to local injection of a GABAA agonist, muscimol into the VM was antagonized by bicuculline, but not by delta-AVA. The present results suggest that delta-AVA may be useful as an antagonist of central pharmacological actions of baclofen.
巴氯芬，一种γ-氨基丁酸B（GABAB）受体激动剂，局部注射到大鼠腹内侧丘脑核（VM）可剂量依赖性、立体特异性和位点特异性地诱发僵住症。巴氯芬诱发的僵住症伴有腓肠肌记录的肌电图（EMG）中的强直活动，这被认为是肢体僵硬程度的一种度量。与巴氯芬共同注射到VM中的δ-氨基戊酸（δ-AVA）可阻止僵住症和肢体僵硬的发展。单独注射到VM中的δ-AVA没有抑制或刺激行为的作用。与δ-AVA相反，GABAA拮抗剂荷包牡丹碱未能拮抗巴氯芬诱发的僵住症。另一方面，由于将GABAA激动剂蝇蕈醇局部注射到VM中引起的僵住症可被荷包牡丹碱拮抗，但不能被δ-AVA拮抗。目前的结果表明，δ-AVA可能作为巴氯芬中枢药理作用的拮抗剂有用。
