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用来自同一大鼠胸主动脉的不同动脉环，比较了用ＮＥ，Ｐｈｅ和Ｋ￣＋作收缩剂时ＧＴＮ的舒血管量效曲线。３×１０ｍｏｌ／Ｌ的ＮＥ，１０￣（－６）ｍｏｌ／Ｌ的Ｐｈｅ和１２４ｍｍｏｌ／Ｌ的Ｋ￣＋收缩血管时ＧＴＮ的量效曲线均为双相Ｓ形。尽管Ｐｈｅ和ＮＥ收缩离体血管的效能大致相同，但ＮＥ收缩的血管环难以被ＧＴＮ所舒张。用Ｋ￣＋作收缩剂时，高浓度的ＧＴＮ不易舒张血管环，而低浓度ＧＴＮ的舒血管作用不受影响。结果表明：ＧＴＮ可能通过两种不同的机制扩张血管；收缩剂类别的差异是ＧＴＮ舒血管量效曲线ＥＣ５０值相差较大的一个重要因素。
Using different arterial rings from the same rat thoracic aorta, the vasorelaxant efficacy curves of GTN were compared with NE, Phe and K ~ + as contractile agents. The dose-response curves of GTN in 3 × 10 mol / L NE, 10 -6 mol / L Phe and 124 mmol / L K + were both biphasic S-shaped. Although the effect of contracting isolated blood vessels from Phe and NE is about the same, the contracting NE rings are less likely to be relieved by GTN. With K ~ + as a contractile agent, high concentration of GTN is not easy to relax vascular ring, and low concentration of GTN vasodilator effect is not affected. The results showed that GTN may dilate blood vessels by two different mechanisms. The difference of contractile properties is an important factor in the large difference between the EC50 values of GTN diastolic blood volume effect curves.