Maul Björn, Krause Winfried, Pankow Kristin, Becker Matthias, Gembardt Florian, Alenina Natalia, Walther Thomas, Bader Michael, Siems Wolf-Eberhard
Institute of Molecular Pharmacology, Berlin, Germany.
FASEB J. 2005 Sep;19(11):1474-81. doi: 10.1096/fj.05-3742com.
Pharmacological and genetic manipulations of the renin-angiotensin system (RAS) have been found to alter the voluntary consumption of alcohol. Here we characterize the role of central angiotensin II (Ang II) in alcohol intake first by using transgenic rats that express an antisense RNA against angiotensinogen and consequently have reduced Ang II levels exclusively in the central nervous system [TGR(ASrAOGEN)680]. These rats consumed markedly less alcohol in comparison to their wild-type controls. Second, Spirapril, an inhibitor of the angiotensin-converting enzyme (ACE), which passes the blood-brain barrier, did not influence the alcohol consumption in the TGR(ASrAOGEN)680, but it significantly reduced alcohol intake in wild-type rats. Studies in knockout mice indicated that the central effect of Ang II on alcohol consumption is mediated by the angiotensin receptor AT1 whereas the AT2 receptor and the bradykinin B2 receptor are not involved. Furthermore, the dopamine concentration in the ventral tegmental area (VTA) is markedly reduced in rats with low central Ang II, strengthening our hypothesis of a role of dopaminergic transmission in Ang II-controlled alcohol preference. Our results indicate that a distinct drug-mediated control of the central RAS could be a promising therapy for alcohol disease.
肾素-血管紧张素系统(RAS)的药理学和基因操作已被发现会改变酒精的自愿摄入量。在此,我们首先通过使用转基因大鼠来表征中枢血管紧张素II(Ang II)在酒精摄入中的作用,这些大鼠表达针对血管紧张素原的反义RNA,因此仅在中枢神经系统中Ang II水平降低[TGR(ASrAOGEN)680]。与野生型对照相比,这些大鼠的酒精摄入量明显减少。其次,能够通过血脑屏障的血管紧张素转换酶(ACE)抑制剂螺普利,对TGR(ASrAOGEN)680的酒精摄入量没有影响,但它显著降低了野生型大鼠的酒精摄入量。基因敲除小鼠的研究表明,Ang II对酒精摄入的中枢作用是由血管紧张素受体AT1介导的,而AT2受体和缓激肽B2受体不参与其中。此外,中枢Ang II水平低的大鼠腹侧被盖区(VTA)中的多巴胺浓度显著降低,这强化了我们关于多巴胺能传递在Ang II控制的酒精偏好中起作用的假设。我们的结果表明,对中枢RAS进行独特的药物介导控制可能是治疗酒精疾病的一种有前景的疗法。