大鼠远端小肠大部切除术后刷状缘膜囊泡中钠依赖性D-葡萄糖转运

Sodium-dependent D-glucose transport in brush-border membrane vesicles after massive distal small bowel resection in the rat.

作者信息

Kwan W C, Quamme G A, Freeman H J

出版信息

Gastroenterology. 1987 Jun;92(6):1987-93. doi: 10.1016/0016-5085(87)90633-0.

Abstract

Massive small intestinal resection in the rat results in both structural and functional changes in the residual small bowel. Sodium-dependent D-glucose transport was examined in brush-border membrane vesicles derived from the proximal small bowel mucosa of male Sprague-Dawley rats 2 and 6 wk after a 66% distal jejunoileal resection or jejunoileal transection. Kinetic characteristics for the low-affinity, high-capacity system and high-affinity, low-capacity system were defined with rapid filtration under conditions of a zero-trans, 100 mM cis-NaSCN gradient. Mucosal weight, protein, and deoxyribonucleic acid content were increased in the residual intestinal segment compared to transected controls and morphometric studies revealed increased villus and crypt heights as well as an increased mitotic index. Postresection mean kinetic parameters for D-glucose transport at 2 wk (low-affinity system: Km, 177.5 +/- 45.1 microM; Vmax, 3.73 +/- 0.99 nmol X mg protein-1 X min-1; and high-affinity system: Km, 6.2 +/- 1.9 microM; Vmax, 0.12 +/- 0.06 nmol X mg protein-1 X min-1) and 6 wk (low-affinity system: Km, 267.8 +/- 83.1 microM; Vmax, 0.06 +/- 0.01 nmol X mg protein-1 X min-1; and high-affinity system: Km, 6.5 +/- 1.1 microM; Vmax, 0.06 +/- 0.01 nmol X mg protein-1 X min-1) were similar to values post-transection at 2 wk (low-affinity system: Km, 280.4 +/- 53.7 microM; Vmax, 3.05 +/- 0.32 nmol X mg protein-1 X min-1; and high-affinity system: Km, 9.1 +/- 1.3 microM; Vmax, 0.17 +/- 0.01 nmol X mg protein-1 X min-1) and 6 wk (low-affinity system: Km, 271.7 +/- 17.5 microM; Vmax, 4.69 +/- 0.23 nmol X protein-1 X min-1; and high-affinity system: Km, 10.6 +/- 4.2 microM; Vmax, 0.16 +/- 0.09 nmol X mg protein-1 X min-1). These kinetic data suggest that the hyperplastic response in adapting proximal small bowel after distal resection is accompanied by a persistence of the membrane functional characteristics for both sodium-dependent D-glucose transport systems despite an altered pattern of enterocyte proliferation and differentiation.

摘要

大鼠的大规模小肠切除会导致残余小肠出现结构和功能变化。在66%远端空肠回肠切除或空肠回肠横断术后2周和6周，对雄性Sprague-Dawley大鼠近端小肠黏膜来源的刷状缘膜囊泡中的钠依赖性D-葡萄糖转运进行了检测。在零转运、100 mM顺式硫氰酸钠梯度条件下，通过快速过滤确定了低亲和力、高容量系统和高亲和力、低容量系统的动力学特征。与横断对照组相比，残余肠段的黏膜重量、蛋白质和脱氧核糖核酸含量增加，形态计量学研究显示绒毛和隐窝高度增加以及有丝分裂指数增加。切除术后2周（低亲和力系统：Km，177.5±45.1 μM；Vmax，3.73±0.99 nmol·mg蛋白⁻¹·min⁻¹；高亲和力系统：Km，6.2±1.9 μM；Vmax，0.12±0.06 nmol·mg蛋白⁻¹·min⁻¹）和6周（低亲和力系统：Km，267.8±83.1 μM；Vmax，0.06±0.01 nmol·mg蛋白⁻¹·min⁻¹；高亲和力系统：Km，6.5±1.1 μM；Vmax，0.06±0.01 nmol·mg蛋白⁻¹·min⁻¹）时D-葡萄糖转运的平均动力学参数与横断术后2周（低亲和力系统：Km，280.4±53.7 μM；Vmax，3.05±0.32 nmol·mg蛋白⁻¹·min⁻¹；高亲和力系统：Km，9.1±1.3 μM；Vmax，0.17±0.01 nmol·mg蛋白⁻¹·min⁻¹）和6周（低亲和力系统：Km，271.7±17.5 μM；Vmax，4.69±0.23 nmol·蛋白⁻¹·min⁻¹；高亲和力系统：Km，10.6±4.2 μM；Vmax，0.16±0.09 nmol·mg蛋白⁻¹·min⁻¹）时的值相似。这些动力学数据表明，尽管肠上皮细胞增殖和分化模式发生改变，但远端切除后近端小肠适应性增生反应伴随着钠依赖性D-葡萄糖转运系统的膜功能特征持续存在。