精神活性药物2C-B对离体大鼠胸主动脉的作用。

The action of the psychoactive drug 2C-B on isolated rat thoracic aorta.

Lobos M, Borges Y, Gonzalez E, Cassels B K

Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago.

Gen Pharmacol. 1992 Nov;23(6):1139-42. doi: 10.1016/0306-3623(92)90301-y.

Abstract

2C-B [2-(4-bromo-2,5-dimethoxyphenyl)ethylamine] elicits concentration-dependent contraction of the rat thoracic aorta (apparent pD2 = 4.55). The maximal contraction (Emax) attained with 2C-B is less than that produced by either norepinephrine (NE) or serotonin (5-HT). 2. Pretreatment with either prazosin (5 x 10(-9) - 10(-8) M) or ketanserin (5 x 10(-9) - 10(-8) M) leads to decreased slopes and Emax in the 2C-B dose-response curves. 3. 2.82 x 10(-5) M 2C-B potentiates the response to low concentrations of NE; 5 x 10(-5) M 2C-B shows similar behaviour, but with reduced Emax. At 10(-6) M 2C-B acts as a competitive 5-HT antagonist; at 2.8 x 10(-5) M, however, it behaves like a non-competitive 5-HT antagonist. 4. Removal of the endothelial lining from the aortal rings only shifts the 2C-B dose-response curve to the left. 5. These results suggest that 2C-B behaves as a partial agonist toward both alpha 1-adrenergic and 5-HT2 serotonergic receptors. The endothelium only seems to act as a diffusional barrier to the drug.

摘要

2C-B [2-(4-溴-2,5-二甲氧基苯基)乙胺] 可引起大鼠胸主动脉浓度依赖性收缩（表观pD2 = 4.55）。2C-B所达到的最大收缩（Emax）小于去甲肾上腺素（NE）或5-羟色胺（5-HT）所产生的最大收缩。2. 用哌唑嗪（5×10⁻⁹ - 10⁻⁸ M）或酮色林（5×10⁻⁹ - 10⁻⁸ M）预处理会导致2C-B剂量-反应曲线的斜率和Emax降低。3. 2.82×10⁻⁵ M的2C-B增强对低浓度NE的反应；5×10⁻⁵ M的2C-B表现出类似行为，但Emax降低。在10⁻⁶ M时，2C-B作为竞争性5-HT拮抗剂起作用；然而，在2.8×10⁻⁵ M时，它表现得像非竞争性5-HT拮抗剂。4. 去除主动脉环的内皮仅使2C-B剂量-反应曲线向左移动。5. 这些结果表明，2C-B对α1-肾上腺素能受体和5-HT2血清素能受体均表现为部分激动剂。内皮似乎仅作为药物的扩散屏障。