Dorce V A, Sandoval M R
Pharmacology Laboratory, Butantan Institute, São Paulo, Brazil.
Toxicon. 1994 Dec;32(12):1641-7. doi: 10.1016/0041-0101(94)90322-0.
This study was designed to investigate the effect of T. serrulatus scorpion venom on dopamine (DA) and gamma amino butyric acid (GABA) concentrations in different regions of the brain. The ratio of homovanillic acid (HVA) to DA, and the glutamic acid decarboxylase (GAD) activity were determined following intravenous or intracerebral venom injections. The increase in the HVA/DA ratio in the striatum after i.v. or intrastriatal injection could indicate an increase in DA turnover. One hour after i.v. injection of the venom GAD activity was shown to be decreased in the striatum and hypothalamus. After 24 hr GAD activity increased in the striatum and decreased in the hypothalamus and brain stem. These results could indicate different effects of the venom on the GABA system in different areas of the brain. After intrastriatal injection of the scorpion venom, the animals showed stereotyped behavior and rotation activity. Following intrahippocampal injection, myoclonus and orofacial automatisms, which constitute pro-convulsive signals, were observed. These behavioral alterations could be, at least in part, related to the GABA and dopamine alterations caused by the venom, since stereotypy, circling behavior and convulsions are dependent on dopamine and/or GABA.
本研究旨在调查锯尾蝎毒液对大脑不同区域多巴胺（DA）和γ-氨基丁酸（GABA）浓度的影响。在静脉内或脑内注射毒液后，测定高香草酸（HVA）与DA的比率以及谷氨酸脱羧酶（GAD）活性。静脉内或纹状体内注射后纹状体中HVA/DA比率的增加可能表明DA周转率增加。静脉注射毒液1小时后，纹状体和下丘脑的GAD活性降低。24小时后，纹状体中的GAD活性增加，而下丘脑和脑干中的GAD活性降低。这些结果可能表明毒液对大脑不同区域的GABA系统有不同影响。纹状体内注射蝎毒后，动物表现出刻板行为和旋转活动。海马内注射后，观察到构成惊厥前信号的肌阵挛和口面部自动症。这些行为改变可能至少部分与毒液引起的GABA和多巴胺改变有关，因为刻板行为、转圈行为和惊厥依赖于多巴胺和/或GABA。
