Gulya K, Budai D, Kása P, Rakonczay Z
J Neurochem. 1984 Jul;43(1):112-9. doi: 10.1111/j.1471-4159.1984.tb06685.x.
The in vivo effects of beta-bungarotoxin (beta-BT) on the acetylcholine (ACh) system were studied in the whole cerebrum and in different brain regions. The effect of beta-BT on cerebral ACh and choline (Ch) contents was time-dependent. The results show that a single intracerebroventricular injection of 1 microgram toxin increased both the ACh and Ch contents in the cortex, hippocampus, and cerebellum, while in the striatum the ACh level was decreased. Ten nanograms of toxin injected into the lateral ventricle twice, on the first and third days, led to a reduced ACh level 2 days after the last treatment. In animals treated with the same dose three times, on the first, third, and fifth days, and sacrificed 2 days after the last injection, the choline acetyltransferase and acetylcholinesterase activities were reduced and the number of muscarinic acetylcholine receptors was decreased. A biphasic effect of the toxin was therefore demonstrated. It is suggested that in the first phase of the toxin effect the increased levels of ACh and Ch may be due to the inhibition of neuronal transmission, while in the second phase, when the elements of the ACh system are reduced, the neuronal degenerating effect of beta-BT plays a significant role.
研究了β-银环蛇毒素（β-BT）在全脑及不同脑区对乙酰胆碱（ACh）系统的体内作用。β-BT对脑内ACh和胆碱（Ch）含量的影响呈时间依赖性。结果显示，脑室内单次注射1微克毒素可使皮质、海马和小脑中的ACh和Ch含量均增加，而纹状体内的ACh水平则降低。在第一天和第三天向侧脑室注射10纳克毒素两次，在最后一次处理后2天导致ACh水平降低。在第一天、第三天和第五天用相同剂量对动物进行三次处理，并在最后一次注射后2天处死，胆碱乙酰转移酶和乙酰胆碱酯酶活性降低，毒蕈碱型乙酰胆碱受体数量减少。因此证明了该毒素具有双相作用。提示在毒素作用的第一阶段，ACh和Ch水平升高可能是由于神经元传递受到抑制，而在第二阶段，当ACh系统的成分减少时，β-BT的神经元变性作用起重要作用。
