Barnes J M, Barnes N M, Costall B, Horovitz Z P, Naylor R J
Postgraduate School of Studies in Pharmacology, University of Bradford, U.K.
Brain Res. 1989 Jul 3;491(1):136-43. doi: 10.1016/0006-8993(89)90095-4.
The effects of angiotensin I and II on basal potassium-induced release of [3H]acetylcholine were investigated in slices of rat entorhinal cortex. Potassium (10-25 mM) produced a concentration-dependent increase in the release of [3H]acetylcholine in the presence of extracellular calcium. Angiotensin II (10(-9)-10(-5) M) (but not angiotensin I) reduced the potassium-induced release of [3H]acetylcholine in a concentration-related manner to 60% of control levels, but did not effect basal tritium release. The effect of angiotensin II was antagonised by [1-sarcosine, 8-threonine] angiotensin II, an angiotensin II receptor antagonist, but not by agents acting on alpha- and beta-adrenoceptors, muscarinic, nicotinic, histamine or 5-hydroxytryptamine receptors nor by the angiotensin converting enzyme (ACE) inhibitor SQ 29852. The results indicate that angiotensin II acting via an angiotensin II receptor can inhibit the release of [3H]acetylcholine in slices of the rat entorhinal cortex. It is hypothesised that the ability of ACE inhibitors to facilitate cognitive processes may be related to a reduced availability of angiotensin II.
在大鼠内嗅皮层切片中研究了血管紧张素I和II对基础钾诱导的[3H]乙酰胆碱释放的影响。在细胞外钙存在的情况下，钾（10 - 25 mM）使[3H]乙酰胆碱的释放呈浓度依赖性增加。血管紧张素II（10(-9)-10(-5) M）（而非血管紧张素I）以浓度相关的方式将钾诱导的[3H]乙酰胆碱释放减少至对照水平的60%，但不影响基础氚释放。血管紧张素II受体拮抗剂[1-肌氨酸，8-苏氨酸]血管紧张素II可拮抗血管紧张素II的作用，但作用于α和β肾上腺素能受体、毒蕈碱、烟碱、组胺或5-羟色胺受体的药物以及血管紧张素转换酶（ACE）抑制剂SQ 29852则不能。结果表明，通过血管紧张素II受体起作用的血管紧张素II可抑制大鼠内嗅皮层切片中[3H]乙酰胆碱的释放。据推测，ACE抑制剂促进认知过程的能力可能与血管紧张素II的可用性降低有关。
