Bamba T, Vaja S, Murphy G M, Dowling R H
Department of Internal Medicine, Shiga University of Medical Science, Japan.
Digestion. 1990;46 Suppl 2:410-23. doi: 10.1159/000200416.
To study the role of the polyamines putrescine, spermidine and spermine and of the enzymes controlling their synthesis (ornithine decarboxylase; ODC) and degradation (diamine oxidase; DAO) along the villus:crypt axis at the crucial early stage of the ileal adaptive response to jejunectomy, we measured polyamine concentrations and the activities of ODC, DAO and alkaline phosphatase (a marker of enterocyte maturity) in epithelial cells isolated by the Weiser technique from villus tips, mid villi, lower villi and crypts 4 days after surgery in transected control (TRC) and jejunectomised rats untreated or given the specific ODC blocker, alpha-difluoromethyl ornithine (DFMO, 2% in drinking water beginning 3 days before surgery). In the TRCs, there was a diminishing villus tip-to-crypt gradient not only in alkaline phosphatase but also in ODC and DAO activities. After jejunectomy, there were up to 93% increases in mean enterocyte ODC activity when compared with the corresponding cell fractions from the TRCs, but in both the control and jejunectomised rats, DFMO treatment markedly inhibited ODC activity (p less than 0.05-0.01) and reduced spermidine and particularly putrescine concentrations (p less than 0.005-0.001) in all four cell fractions. Only 4 days post-operation, jejunectomy stimulated a significant increase in ileal wet weight but DFMO treatment completely prevented this adaptive response and significantly reduced segmental intestinal weight (mg/cm) in the TRCs. These results (i) extend our knowledge of polyamines and related enzymes along the villus:crypt gradient in the normal intestine, (ii) provides the first data on these variables after resection, and (iii) lend further support to the hypothesis that changes in enterocyte ODC activity and in putrescine and spermidine concentrations play an important role in initiating the ileal adaptive response to proximal small bowel resection in the rat.
为研究多胺（腐胺、亚精胺和精胺）以及控制其合成（鸟氨酸脱羧酶；ODC）和降解（二胺氧化酶；DAO）的酶在空肠切除术后回肠适应性反应关键早期沿绒毛：隐窝轴的作用，我们采用韦泽技术从手术4天后的横断对照（TRC）大鼠和空肠切除大鼠的绒毛顶端、绒毛中部、绒毛下部和隐窝中分离上皮细胞，测量了多胺浓度以及ODC、DAO和碱性磷酸酶（肠上皮细胞成熟的标志物）的活性。这些空肠切除大鼠未接受治疗或给予特异性ODC阻滞剂α - 二氟甲基鸟氨酸（DFMO，术前3天开始在饮用水中添加2%）。在TRC大鼠中，不仅碱性磷酸酶，而且ODC和DAO活性都存在从绒毛顶端到隐窝逐渐降低的梯度。空肠切除术后，与TRC大鼠相应细胞组分相比，平均肠上皮细胞ODC活性增加高达93%，但在对照大鼠和空肠切除大鼠中，DFMO处理均显著抑制ODC活性（p < 0.05 - 0.01），并降低了所有四个细胞组分中亚精胺尤其是腐胺浓度（p < 0.005 - 0.001）。术后仅4天，空肠切除术就刺激回肠湿重显著增加，但DFMO处理完全阻止了这种适应性反应，并显著降低了TRC大鼠的节段性肠重（mg/cm）。这些结果（i）扩展了我们对正常肠道中沿绒毛：隐窝梯度的多胺及相关酶的认识，（ii）提供了切除术后这些变量的首个数据，（iii）进一步支持了以下假说：肠上皮细胞ODC活性以及腐胺和亚精胺浓度的变化在启动大鼠回肠对近端小肠切除的适应性反应中起重要作用。
