Davila D, Davila T
Arch Int Pharmacodyn Ther. 1975 Mar;214(1):53-61.
The accumulation of 3H-metaraminol in incubated lung tissue of the rat was examined in vitro. Lung tissue concentrated tritium after incubation with 3H-metaraminol. This uptake proceeds against a concentration gradient and shows saturation kinetics (Km 12.5 X 10(-7) M and Vmax 2.105 nM/g/15 min.) with great affinity for 3H-metaraminol. The accumulation of 3H-metaraminol is dependent of temperature and energy supply, and requires the presence of sodium ions. The loss of accumulated radioactivity showed the possibility that a small fraction of metaraminol is apparently firmly boune (e.g. neuronal sites), while a greater portion is taken up by extraneuronal structures (e.g. capillary endothelial cells). The first localization could represent uptake-1 and the second uptake-2. The results obtained also confirm the important role of the lungs as an organ which participates in the fate of endogenous substances and drugs.
在体外研究了3H-间羟胺在大鼠离体肺组织中的蓄积情况。肺组织在与3H-间羟胺孵育后会浓聚氚。这种摄取是逆浓度梯度进行的，呈现饱和动力学（Km为12.5×10⁻⁷ M，Vmax为2.105 nM/g/15分钟），对3H-间羟胺具有高度亲和力。3H-间羟胺的蓄积取决于温度和能量供应，且需要钠离子的存在。蓄积放射性的损失表明，一小部分间羟胺显然牢固结合（如神经元部位），而较大部分被神经外结构（如毛细血管内皮细胞）摄取的可能性。第一种定位可能代表摄取-1，第二种代表摄取-2。所获得的结果也证实了肺作为参与内源性物质和药物命运的器官的重要作用。
