大鼠四个不同脑区埋藏胆碱能神经阻断剂对神经源性应激反应的影响

本实验采用固体药物埋藏的方法,将阿托品、六烃季铵分别埋藏于大鼠下丘脑室旁核(PVH)附近,将阿托品分别埋藏于腹侧海马、背侧海马和丘脑。以麻醉状态下大鼠坐骨神经损伤性刺激(神经源性应激)作为应激条件,血浆皮质酮浓度变化作为观察指标。结果为:阿托品和六烃季铵分别埋藏于PVH后5d,坐骨神经损伤性刺激后30和60min血浆皮质酮浓度的升高,均受到显著的抑制,皮质酮总反应量也较埋药前明显下降(P<0.01)。将阿托品埋藏于腹侧海马后5 d,刺激后血浆皮质酮反应,也受到一定程度的抑制。而阿托品埋藏于背侧海马和丘脑,对损伤性应激引起的血浆皮质酮变化,未见显著影响(P>0.05)。结果表明,脑内PVH和腹侧海马内有胆碱能接受系统,对损伤性应激反应具有调节作用,而且这一作用存在着部位特异性。

Effects of implantation of the Cholinergic Antagonists into Four Different Brain Areas on Neurogenic Stress Response in Rats.

The present study was undertaken to observe the effect of implantation of the anti-cholinergic agents into different brain areas: hypothalamic paraventricular nucleus (PVH), ventral and dorsal hippocampus, thalamus; and to analyse their effect on the neurogenic stress response. The experiment was performed in 60 anesthetized rats with sciatic nerve stimulation. It was found that atropine and hexamethonium implantation into PVH markedly inhibited the adrenocortical response evoked by sciatic stimuli at 30 and 60 min following stimulation. Vehicle implant in the same region was ineffective, suggesting that the action of the agent was specific in the PVR The implantation of atropine into the ventral hippocampus was effective at 30 min following onset of stimulation, and atropine implant in the dorsal hippocampus was ineffective. The above data suggest that atropine and hexamethonium have effect of inhibiting plasma corticosterone level following sciatic stimulation by acting through cholinergic M and N receptors on PVH and nearby neural tissue and that cholinergic M receptors in the ventral hippocampus may be involved in the modulation of stress response.