It was reported that nitric oxide (NO) donors increased the permeability of water-soluble compounds across intestinal membrane with neither loss of cell viability nor release of lactate dehydrogenase. Therefore, the detail mechanism of action of NO donors on the gastrointestinal membrane has yet to be clarified. We previously reported the possibility of the enhancing effect of the NO donor on the membrane permeability via transcellular route. The purpose of this study is to clarify the mechanism of the membrane permeation-enhancing effect via the transcellular route by sodium nitroprusside (SNP), which is one of the NO donors. The effect of SNP on membrane permeation was examined by the in vitro sac method using rat jejunum. SNP increased the membrane permeation of rhodamine 123 same as using N-acetyl-L-cysteine and dithiothreitol which removes unstirred water layer (UWL). Moreover, SNP increased the membrane permeation of antipyrine and β-naphthol, which are transcellular markers. And it was also investigated the expression levels of mucins (MUCs) which are construction component of UWL and the slight change of MUCs expression by SNP was shown. It was suggested that the expression balance of MUCs is necessary to regulate transcellular permeation, and SNP may affect to UWL. This finding was considered useful for highly lipophilic drugs for which membrane permeation is restricted by the UWL.

中文翻译：

---

硝普钠通过跨细胞途径增强大鼠空肠中的吸收。

据报道，一氧化氮 (NO) 供体增加了水溶性化合物跨肠膜的渗透性，既不丧失细胞活力，也不释放乳酸脱氢酶。因此，NO供体对胃肠膜作用的详细机制尚待阐明。我们之前报道了 NO 供体通过跨细胞途径增强膜通透性的可能性。本研究的目的是阐明硝普钠 (SNP) 是 NO 供体之一，通过跨细胞途径增强膜渗透作用的机制。通过使用大鼠空肠的体外囊法检查 SNP 对膜渗透的影响。SNP 增加了罗丹明 123 的膜渗透，与使用 N-乙酰基-L-半胱氨酸和二硫苏糖醇去除未搅拌水层 (UWL) 相同。此外，SNP 增加了安替比林和 β-萘酚的膜渗透，它们是跨细胞标志物。并且还研究了作为UWL构建成分的粘蛋白(MUCs)的表达水平，显示了SNP对MUCs表达的轻微变化。表明MUCs的表达平衡是调节跨细胞渗透所必需的，SNP可能影响UWL。这一发现被认为对膜渗透受 UWL 限制的高度亲脂性药物有用。并且还研究了作为UWL构建成分的粘蛋白(MUCs)的表达水平，显示了SNP对MUCs表达的轻微变化。表明MUCs的表达平衡是调节跨细胞渗透所必需的，SNP可能影响UWL。这一发现被认为对膜渗透受 UWL 限制的高度亲脂性药物有用。并且还研究了作为UWL构建成分的粘蛋白(MUCs)的表达水平，显示了SNP对MUCs表达的轻微变化。表明MUCs的表达平衡是调节跨细胞渗透所必需的，SNP可能影响UWL。这一发现被认为对膜渗透受 UWL 限制的高度亲脂性药物有用。