大鼠食管下端括约肌氮能神经元发育的铺片研究

The development of nitrergic neurons in lower esophageal sphincter of rats

目的探讨食管下端括约肌肌间神经丛氮能神经元的生后发育规律。方法分别取生后第1d、7d、14d、21d、30d、成年大鼠的食管下端括约肌及食管体,应用铺片技术与NADPH-d酶组织化学法,定性、定量研究食管下端括约肌与食管体的肌间神经丛内氮能神经元的发育变化。结果随着日龄的增加,食管下端括约肌肌间神经丛内氮能神经元成熟度逐渐增加,神经元密度逐渐下降,从生后第1d的(293.7±47.8)个/mm2,逐渐下降为生后第30d的(25.9±9.9)个/mm2,而食管体的神经元密度明显低于相应组别的食管下端括约肌(P<0.05);神经元大小从生后第1d的(129.8±45.9)μm2增加到生后第30d的(428.3±122.1)μm2,基本达到成年组水平,各组间差异有显著性意义(P<0.01)。结论大鼠食管下端括约肌肌间神经丛内的氮能神经元在生后继续发育,以哺乳期变化为著,至生后30d时基本成熟;与食管体比较,食管下端括约肌氮能神经元更为密集。

Objective To explore the postnatal development of nitrergic neurons in the myenteric plexus of the lower esophageal sphincter （LES） in rats. Methods LES and esophageal body （EB） were collected from rats at post-partum days 1, 7, 14, 21, and 30. Adult esophagus was used as control. The whole mount preparation of the esophageal myenteric plexus was immuostained with anti- NADPH-diaphorase Ab. A qualitative and quantitative study of the developmental change in nitrergic neurons was conducted. Results With maturity, the degree of nitrergic neurons increased. Cytoplasm stained deeper; neurofliaments and axons became longer and larger. The myenteric plexus was distributed regularly and sparsely. The density of neurons decreased gradually in LES, from （293.7 ± 47. 8） neurons/mm^2 in the Day 1 group to （25.9± 9. 9）neurons/ mm^2 in the Day 30 group. However the density in the EB was much lower in corresponding groups of LES （P〈0. 05）. The per neuron area was （129. 8 ± 45.9）μm^2 in Day 1 group, （428.3 ± 122. 1）μm^2 in the Day 30 group, （P〈0.01） and （420. 3 ± 146. 9）μm^2 for the adult group. Meanwhile, the cytoplasm/nucelus ratio increased gradually with maturity. There was no obvious difference between the Day 30 group（2. 83 ± 0. 88） and the adult group （3.10± 0. 99）（P〉 0. 05）. Conclusions Nitrergic neurons in myenteric plexus of LES in rats continue their development after birth, especially during lactation, and maturate gradually till postnatal Day 30. Compared to esophageal body, the nitrergic neurons is more dense in LES.