Nichols B L, Carrazza F, Nichols V N, Putman M, Johnston P, Rodrigues M, Quaroni A, Shiner M
USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030.
J Pediatr Gastroenterol Nutr. 1992 May;14(4):371-9. doi: 10.1097/00005176-199205000-00002.
The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.
在年轻营养不良婴儿中观察到的对膳食葡萄糖和其他碳水化合物敏感的慢性腹泻与不同程度的斑片状黏膜绒毛萎缩有关。为了探究这种消化不耐受发病机制中的内在黏膜功能，我们对临床获取的黏膜活检样本的刷状缘酶蛋白进行了免疫组织学研究。我们使用了一组针对人刷状缘氨肽酶、蔗糖酶/异麦芽糖酶（SI）、麦芽糖酶和乳糖酶蛋白的单克隆抗体。14名受试者中有11名的隐窝和绒毛中SI表达强烈且均匀；然而，3名受试者中SI呈镶嵌模式表达。麦芽糖酶和乳糖酶偶尔缺失，但更常见的是呈镶嵌分布表达。刷状缘酶蛋白的镶嵌表达在与正常肠道组织学相关的先天性酶缺乏症中已有报道。我们报告刷状缘酶蛋白的镶嵌表达是与慢性腹泻婴儿黏膜病理病变相关的一种功能改变。我们的观察对刷状缘酶活性的个体发育调控的现有概念提出了挑战。
