L-NG-硝基精氨酸对大鼠离体肛尾肌交感神经诱导的收缩及去甲肾上腺素释放的影响。

The influence of L-NG-nitro-arginine on sympathetic nerve induced contraction and noradrenaline release in the rat isolated anococcygeus muscle.

Brave S R, Bhat S, Hobbs A J, Tucker J F, Gibson A

Biomedical Sciences Division, King's College London, UK.

J Auton Pharmacol. 1993 Jun;13(3):219-25. doi: 10.1111/j.1474-8673.1993.tb00269.x.

Abstract

The possibility of an interaction between the motor sympathetic and inhibitory non-adrenergic, non-cholinergic (NANC) nerves in the rat anococcygeus was investigated using L-NG-nitro-arginine (L-NOARG), an inhibitor of L-arginine: NO synthase. 2. L-NOARG (50 microM) increased contractions induced by field stimulation (20 s trains; 0.5-40 Hz); overall, the frequency-response curve was displaced six-fold to the left. D-NOARG (50 microM) was without effect. 3. The potentiation produced by L-NOARG was reversed by 200 microM L-, but not D-, arginine. 4. L-NOARG had no effect on contractions induced by exogenous noradrenaline (NA) or on field stimulation-induced overflow of tritium from muscles previously loaded with [3H]-NA. 5. It is concluded that the endogenous nitrate NANC transmitter does not influence release of NA from the sympathetic nerves and the potentiation of contractions induced by field stimulation in the presence of L-NOARG most probably results from removal of the opposing relaxing influence of concomitantly released NANC transmitter.

摘要

使用L-精氨酸：一氧化氮合酶抑制剂L-NG-硝基-精氨酸（L-NOARG），研究了大鼠肛门尾骨肌中运动交感神经与抑制性非肾上腺素能、非胆碱能（NANC）神经之间相互作用的可能性。2. L-NOARG（50微摩尔）增加了场刺激（20秒串刺激；0.5 - 40赫兹）诱导的收缩；总体而言，频率-反应曲线向左移位了6倍。D-NOARG（50微摩尔）无作用。3. L-NOARG产生的增强作用被200微摩尔L-精氨酸逆转，但未被D-精氨酸逆转。4. L-NOARG对外源性去甲肾上腺素（NA）诱导的收缩或对场刺激诱导的先前用[3H]-NA标记的肌肉中氚的溢出均无作用。5. 得出的结论是，内源性硝酸盐NANC递质不影响交感神经释放NA，并且在存在L-NOARG的情况下场刺激诱导的收缩增强最可能是由于去除了伴随释放的NANC递质的相反舒张作用。