Calado T de J, Mandarim-de-Lacerda C A, Coutinho V B, Robalinho T I, Countinho H B
Department of Morphology, Federal University of Alagoas, Brazil.
Ital J Anat Embryol. 1994 Jul-Sep;99(3):171-80.
Intestinal closure is the blocking of biopolymers transferred across the small intestine epithelium that coincides with gut maturation. Sixty-one fetuses of D. albiventris, 45 to 55 mm in Crown-Rump length, were studied. Forty-one fetuses were injected subcutaneously with hydrocortisone hemisuccinate (0.4 mg/15.0 g of body weight) daily for 7 days in order to produce intestinal closure (TA). The control group (CA), consisted of twenty fetuses. Seven days after injection several fragments from the duodenum and ileum were prepared for transmission electron microscopic examination. Microvillus lengths and widths were determined from micrographs (final magnification: 100,000 x). The volume of the microvillus was calculated as the volume of the cylinder. Quantitative differences of the microvilli between the treated and control groups taken from duodenum and ileum material were noted. The distribution of the microvilli in the apical part of the enterocytes was more irregular in controls than in the TA group. Quantitatively, microvillus length in the duodenum was more than 50 per cent greater in TA than in CA and more than 30 per cent greater in TA than in CA in the ileum. Consequently, microvilli volume in the duodenum in TA was about 65 per cent greater than in CA and about 33 per cent greater than in CA in the ileum. Microvilli width presented little change and no statistically significant differences were found between TA and CA in either the duodenum or the ileum. These changes in the microvilli of the treated animals most probably indicate improvement in the absorptive function of the epithelium.
肠道闭锁是指在肠道成熟过程中，生物聚合物跨小肠上皮细胞转运被阻断。研究了61只白腹豚鼠胎儿，其顶臀长为45至55毫米。为了诱导肠道闭锁（TA组），对41只胎儿每天皮下注射半琥珀酸氢化可的松（0.4毫克/15.0克体重），持续7天。对照组（CA组）由20只胎儿组成。注射7天后，制备十二指肠和回肠的多个片段用于透射电子显微镜检查。从显微照片（最终放大倍数：100,000倍）确定微绒毛的长度和宽度。微绒毛的体积按圆柱体体积计算。记录了取自十二指肠和回肠材料的治疗组与对照组之间微绒毛的定量差异。对照组中，肠上皮细胞顶端部分微绒毛的分布比TA组更不规则。定量分析显示，TA组十二指肠微绒毛长度比CA组长50%以上，回肠微绒毛长度比CA组长30%以上。因此，TA组十二指肠微绒毛体积比CA组大65%左右，回肠微绒毛体积比CA组大33%左右。微绒毛宽度变化不大，TA组与CA组在十二指肠或回肠中均未发现统计学上的显著差异。治疗动物微绒毛的这些变化很可能表明上皮细胞吸收功能有所改善。
