Hardin J A, Buret A, Meddings J B, Gall D G
Gastrointestinal Research Group, Health Sciences Centre, University of Calgary, Alberta, Canada.
Am J Physiol. 1993 Feb;264(2 Pt 1):G312-8. doi: 10.1152/ajpgi.1993.264.2.G312.
The effect of acute in vivo epidermal growth factor (EGF) exposure on intestinal absorptive surface area was examined in blind jejunal loops in New Zealand White rabbits (500-900 g). Brush-border surface area was assessed by electron microscopy at 30 and 120 min, and total surface area was assessed by the fluorophore 1-[4-(trimethylamino)phenyl)]-6-phenylhexatriene (TMA-DPH) at 10 and 60 min after EGF exposure. Mucosa obtained at 120 min was also used for morphometrics and analysis of membrane composition and fluidity. Brush-border surface area was significantly increased in EGF-treated tissue after 30 (42%) and 120 min (60%). Total absorptive surface area measured by TMA-DPH was increased more than twofold after 10 and 60 min EGF exposure. The increase in absorptive surface area was abolished by pretreatment with intravenous verapamil. Mucosal morphometrics and membrane sucrase activity, total phospholipids, cholesterol content, cholesterol-to-phospholipid ratio, phospholipid species (wt%), phospholipid fatty acid composition, and fluidity did not differ between control and EGF-treated tissue. These findings indicate that EGF can rapidly increase brush-border surface area by a mechanism that appears to be due to a redistribution of existing performed microvillus plasma membrane.
在体重500 - 900克的新西兰白兔的空肠盲袢中，研究了急性体内表皮生长因子（EGF）暴露对肠道吸收表面积的影响。在EGF暴露后30分钟和120分钟，通过电子显微镜评估刷状缘表面积；在EGF暴露后10分钟和60分钟，通过荧光团1-[4-(三甲基氨基)苯基)]-6-苯基己三烯（TMA-DPH）评估总表面积。在120分钟时获取的黏膜也用于形态计量学以及膜成分和流动性分析。在30分钟（增加42%）和120分钟（增加60%）后，EGF处理的组织中刷状缘表面积显著增加。在EGF暴露10分钟和60分钟后，通过TMA-DPH测量的总吸收表面积增加了两倍多。静脉注射维拉帕米预处理可消除吸收表面积的增加。对照组织和EGF处理的组织之间，黏膜形态计量学、膜蔗糖酶活性、总磷脂、胆固醇含量、胆固醇与磷脂的比率、磷脂种类（重量%）、磷脂脂肪酸组成和流动性没有差异。这些发现表明，EGF可通过一种似乎是由于现有微绒毛质膜重新分布的机制迅速增加刷状缘表面积。
