Ross S B, Gosztonyi T
Naunyn Schmiedebergs Arch Pharmacol. 1975;288(2-3):283-93. doi: 10.1007/BF00500533.
The uptake of bretylium-(N-3H-methyl) iodide in the rat heart atrium in vitro was examined. The uptake was linear for at least 1 hr and was strongly inhibited by (+)-amphetamine, (-)-noradrenaline, desipramine, cocaine, DSP 4 [N-(2-bromobenzyl)-N-(2-chloroethyl)ethylamine hydrochloride], guanethidine and ouabain. The amphetamine sensitive part of the uptake was almost completely abolished by pre-treatment of the rats with 6-hydroxydopamine and was dependent on the presence of sodium ions. Reserpine had no effect. (+)-Amphetamine but not desipramine caused an increase of the efflux of bretylium from the tissue. The apparent Km value of the active bretylium uptake was 3 x 10(-6) M, which was 10 times higher than that of the uptake of (-)-noradrenaline in the rat heart atrium (Km = 3 x 10(-7) M). The inhibition constants (Ki) for bretylium in inhibiting the noradrenaline uptake and for (-)-noradrenaline in inhibiting the bretylium uptake were 7 x 10(-6) M and 4 x 10(-7) M, respectively. The results obtained support the hypothesis that bretylium is taken up by the same mechanism as that carrying noradrenaline into the nerve terminals but is not bound in the noradrenaline storage vesicles.
研究了离体大鼠心房对（N - 3H - 甲基）碘化溴苄铵的摄取情况。摄取至少1小时呈线性，且受到（+） - 苯丙胺、（ - ） - 去甲肾上腺素、地昔帕明、可卡因、DSP 4 [N - （2 - 溴苄基） - N - （2 - 氯乙基）乙胺盐酸盐]、胍乙啶和哇巴因的强烈抑制。摄取中对苯丙胺敏感的部分在用6 - 羟基多巴胺预处理大鼠后几乎完全消除，且依赖于钠离子的存在。利血平无作用。（+） - 苯丙胺而非地昔帕明导致溴苄铵从组织中的流出增加。活性溴苄铵摄取的表观Km值为3×10（-6）M，这比大鼠心房中（ - ） - 去甲肾上腺素摄取的Km值（Km = 3×10（-7）M）高10倍。溴苄铵抑制去甲肾上腺素摄取的抑制常数（Ki）和（ - ） - 去甲肾上腺素抑制溴苄铵摄取的抑制常数分别为7×10（-6）M和4×10（-7）M。所得结果支持这样的假说，即溴苄铵与将去甲肾上腺素转运到神经末梢的机制相同，但不结合在去甲肾上腺素储存囊泡中。
