Trendelenburg U
Naunyn Schmiedebergs Arch Pharmacol. 1987 Jul;336(1):33-6. doi: 10.1007/BF00177748.
Segments of the rabbit main pulmonary artery and of its two branches were exposed for 10 min to 50 nmol/l 3H-(+/-)-isoprenaline, and the accumulation of tritium in the tissue was determined; COMT was inhibited in all experiments. 1. The accumulation of the tritium label was sensitive to 3-O-methyl-isoprenaline (OMI), showing that this vascular smooth muscle possesses uptake2. 2. In the presence of 0.01 to 1 mumol/l (-)-noradrenaline, the accumulation of tritium was depressed (in a concentration-dependent manner). This decline involved the OMI-sensitive accumulation of 3H-isoprenaline. 3. The presence of any one of three selective alpha 1-adrenoceptor antagonists (1 mumol/l prazosin, 1 mumol/l WB4101, 10 mumol/l corynanthine) prevented the effect of 1 mumol/l (-)-noradrenaline on the accumulation of tritium. However, in the absence of (-)-noradrenaline, the three antagonists failed to affect the accumulation of tritium. 4. 10 mumol/l nicorandil caused the accumulation of tritium to increase. 5. As stimulation of alpha 1-adrenoceptors is known to result in depolarization, and as nicorandil is known to hyperpolarize this smooth muscle, it is concluded that the resting membrane potential modulates uptake2.
将兔主肺动脉及其两个分支的部分暴露于50 nmol/l的3H-(+/-)-异丙肾上腺素中10分钟，然后测定组织中氚的蓄积量；在所有实验中儿茶酚-O-甲基转移酶（COMT）均受到抑制。1. 氚标记物的蓄积对3-O-甲基异丙肾上腺素（OMI）敏感，表明该血管平滑肌具有摄取功能2。2. 在存在0.01至1 μmol/l（-）-去甲肾上腺素的情况下，氚的蓄积受到抑制（呈浓度依赖性）。这种下降涉及3H-异丙肾上腺素对OMI敏感的蓄积。3. 三种选择性α1-肾上腺素能受体拮抗剂中的任何一种（1 μmol/l哌唑嗪、1 μmol/l WB4101、10 μmol/l育亨宾）的存在均可阻止1 μmol/l（-）-去甲肾上腺素对氚蓄积的影响。然而，在不存在（-）-去甲肾上腺素的情况下，这三种拮抗剂未能影响氚的蓄积。4. 10 μmol/l尼可地尔导致氚的蓄积增加。5. 由于已知刺激α1-肾上腺素能受体会导致去极化，且已知尼可地尔会使该平滑肌超极化，因此得出结论，静息膜电位调节摄取功能2。
