Gil-Vernet J M, Marhuenda C, Boix-Ochoa J, Mourelle M, Mearin F, Salas A, Guarner F, Moncada S, Malagelada J R
Departamento de Cirugía Pediátrica, Hospital Universitario Materno-Infantil Vall d'Hebrón, Barcelona.
Cir Pediatr. 1994 Jul;7(3):110-4.
Hirschsprung's disease may be due to impaired nonadrenergic-noncholinergic inhibitory input in the aganglionic segment of the colon. It has been suggested that nitric oxide (NO) might be the lacking neurotransmitter. Thus, our specific aims were to determine in ganglionic and aganglionic segments: 1. The activity of the NO synthetase (NO-S); 2. The location of this enzyme; and 3. The "in vitro" basal motor activity of the muscle strips and their responses to an NO donor and to an NO antagonist.
NO synthetase activity was quantified in samples of tissue from both aganglionic and ganglionic segments obtained during surgery in 6 patients with Hirschsprung's disease by the transformation of 14C-L-arginine into 14C-L-citrulline in tissue homogenates. Immunohistochemical staining of the tissues was performed using a polyclonal antibody raised against a peptide sequence of rat brain NO synthetase. Furthermore, in 2 patients we measured "in vitro" the tonic response of muscle strips to an exogenous NO donor (sodium nitroprusside) and to an NO antagonist (L-NAME).
NOS activity was undetectable in every aganglionic segment whereas it was present in all ganglionic segments (0.49 +/- 0.09 pmol citrulina/mg.min; mean +/- SE). Immunohistochemically, NO-S was absent in the myenteric plexus of aganglionic segments and it was present in ganglionic segments. "In vitro" basal motor activity of ganglionic segments was normal, with presence of low-frequency contractions (LFC) and summation contraction (SC); in aganglionic segments SC were absent. Sodium nitroprusside induced a marked relaxation (90% from basal) in muscle strips, both aganglionic and ganglionic, precontracted with bethanocol.(ABSTRACT TRUNCATED AT 250 WORDS)
先天性巨结肠病可能是由于结肠无神经节段中去甲肾上腺素能-非胆碱能抑制性输入受损所致。有人提出一氧化氮（NO）可能是缺失的神经递质。因此，我们的具体目标是在有神经节和无神经节段中确定：1. 一氧化氮合酶（NO-S）的活性；2. 该酶的位置；3. 肌条的“体外”基础运动活性及其对NO供体和NO拮抗剂的反应。
通过在组织匀浆中将14C-L-精氨酸转化为14C-L-瓜氨酸，对6例先天性巨结肠病患者手术中获取的无神经节和有神经节段的组织样本中的NO合酶活性进行定量。使用针对大鼠脑NO合酶肽序列产生的多克隆抗体对组织进行免疫组织化学染色。此外，在2例患者中，我们“体外”测量了肌条对外源性NO供体（硝普钠）和NO拮抗剂（L-精氨酸甲酯）的强直反应。
在每个无神经节段均未检测到NOS活性，而在所有有神经节段均存在（0.49±0.09 pmol瓜氨酸/mg·min；平均值±标准误）。免疫组织化学显示，无神经节段的肌间神经丛中不存在NO-S，而有神经节段中存在。有神经节段的“体外”基础运动活性正常，存在低频收缩（LFC）和总和收缩（SC）；无神经节段不存在SC。硝普钠使预先用氨甲酰甲胆碱收缩的无神经节和有神经节的肌条产生明显松弛（从基础值松弛90%）。（摘要截短于250字）
