Lahtinen H, Brankack J, Koivisto E, Riekkinen P J
Department of Neurology, University of Kuopio, Finland.
Brain Res Bull. 1992 Dec;29(6):837-41. doi: 10.1016/0361-9230(92)90152-n.
Gamma-hydroxybutyrate (GHB) was intracortically applied in two doses (first 10 and then 20 mg/ml) to awake Wistar rats using microdialysis. Simultaneously, EEG and the release of somatostatin-like immunoreactivity (SLI) were measured from the frontal cortex. Intracerebrally administered GHB induced cortical epileptogenic spikes, but not high voltage spindles (HVS) as reported after systemic administration, and seizures with myoclonic jerks and contraversive head movements. Compared to the basal level, GHB (10 mg/ml) initially increased the release of SLI (p < 0.05). However, when the frequency of spikes and seizures rose rapidly (p < 0.001), SLI release decreased significantly (p < 0.001). Minimum release of SLI occurred when seizures were most frequent (during perfusion with 20 mg/ml GHB), while after removal of the drug it rose above the basal level (p < 0.05). According to these results, intracortically applied GHB increases the release of SLI in the surrounding tissue. However, further exposure of GHB leads to a manifestation of epileptic spikes and seizures, during which the release of SLI is significantly attenuated. This suggests that release of somatostatin is affected during epileptic phenomena induced also by intracortical GHB application.
采用微透析技术，将γ-羟基丁酸（GHB）以两种剂量（先10mg/ml，后20mg/ml）皮质内注射到清醒的Wistar大鼠体内。同时，测量额叶皮质的脑电图（EEG）以及生长抑素样免疫反应性物质（SLI）的释放。脑内注射GHB诱发了皮质癫痫样棘波，但未诱发全身给药后所报道的高电压纺锤波（HVS），并引发了伴有肌阵挛性抽搐和头部扭转运动的癫痫发作。与基础水平相比，GHB（10mg/ml）最初增加了SLI的释放（p<0.05）。然而，当棘波和癫痫发作频率迅速上升时（p<0.001），SLI释放显著减少（p<0.001）。当癫痫发作最频繁时（在灌注20mg/ml GHB期间），SLI释放降至最低，而在去除药物后，其释放量上升至基础水平以上（p<0.05）。根据这些结果，皮质内注射GHB可增加周围组织中SLI的释放。然而，进一步接触GHB会导致癫痫样棘波和癫痫发作的出现，在此期间SLI的释放显著减弱。这表明在皮质内注射GHB所诱发的癫痫现象中，生长抑素的释放受到了影响。
