Gustafsson L E, Wiklund C U, Wiklund N P, Persson M G, Moncada S
Dept of Physiology, Karolinska Institutet, Stockholm, Sweden.
Biochem Biophys Res Commun. 1990 Nov 30;173(1):106-10. doi: 10.1016/s0006-291x(05)81028-9.
NG-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide synthesis, markedly enhanced tonic ("hump") responses to transmural stimulation in guinea pig ileum longitudinal muscle. The enhancement of the hump responses was probably due to a prejunctional effect on substance P-like neurotransmission, since the action of L-NMMA was exerted also in the presence of atropine, and since responses to substance P, a mimic of nerve stimulation, were unaffected by L-NMMA as were cholinergic twitch responses and the overflow of [3H]choline. Further in support, the hump responses were blocked by the substance P antagonist Spantide. All effects of L-NMMA were stereospecifically reversed by L-arginine. Endogenous nitric oxide thus selectively modulates peptidergic neurotransmission in the gut.
NG-单甲基-L-精氨酸（L-NMMA）是一种一氧化氮合成抑制剂，它能显著增强豚鼠回肠纵行肌对透壁刺激的紧张性（“峰”）反应。峰反应增强可能是由于对P物质样神经传递的节前效应，因为L-NMMA的作用在阿托品存在时也能发挥，而且对P物质（神经刺激的模拟物）的反应、胆碱能抽搐反应以及[3H]胆碱的溢出不受L-NMMA影响，这与L-NMMA对它们的作用方式相同。进一步的证据是，峰反应被P物质拮抗剂Spantide阻断。L-NMMA的所有作用都能被L-精氨酸立体特异性地逆转。因此，内源性一氧化氮可选择性地调节肠道中的肽能神经传递。
