Ray M, Dinda P K, Beck I T
Department of Medicine, Queen's University, Hôtel Dieu Hospital, Kingston, Ontario, Canada.
Gastroenterology. 1989 Feb;96(2 Pt 1):345-54. doi: 10.1016/0016-5085(89)91558-8.
To study the mechanism of morphologic and microvascular effects of intraluminal ethanol, we perfused jejunal segments of the dog with 6% (wt/vol) ethanol for 0 (control), 10, 20, 30, 60, and 90 min, and measured the time-dependent changes in (a) the prevalence of villi with epithelial damage (i.e., villi with intact blebs plus those with broken blebs) and those without epithelial damage (undamaged villi), (b) the height of the villus core and the patency of lacteals, (c) jejunal albumin loss, and (d) permeability of microvessels of the villus tip by colloidal carbon vascular labeling. We found that (a) the prevalence of villi with epithelial damage or with intact bleb increased progressively during the first 20 min of ethanol perfusion and then declined gradually; (b) the height of the villus core and the patency of lacteals in the undamaged villi and in those with intact bleb decreased during the first 20 min and then gradually increased; and (c) jejunal albumin loss and the prevalence of villi with carbon labeling increased for the first 30 min, after which the former declined gradually whereas the latter remained at a plateau. These findings suggest that contraction of the villus core and compression of the lymphatics are the primary cause of ethanol-induced epithelial damage, which is accentuated by increased microvascular permeability and consequent protein leakage. The mechanism of recovery of most parameters, in spite of continuous ethanol perfusion, remains to be investigated.
为研究腔内乙醇对形态学和微血管的影响机制，我们用6%（重量/体积）乙醇灌注犬的空肠段0（对照）、10、20、30、60和90分钟，并测量以下各项随时间的变化：（a）有上皮损伤的绒毛（即有完整泡状突起的绒毛加上有破裂泡状突起的绒毛）和无上皮损伤的绒毛（未损伤绒毛）的发生率；（b）绒毛核心高度和乳糜管通畅情况；（c）空肠白蛋白丢失；（d）通过胶体碳血管标记法测量绒毛尖端微血管的通透性。我们发现：（a）在乙醇灌注的前20分钟内，有上皮损伤或有完整泡状突起的绒毛发生率逐渐增加，然后逐渐下降；（b）未损伤绒毛和有完整泡状突起的绒毛中，绒毛核心高度和乳糜管通畅情况在最初20分钟内下降，然后逐渐增加；（c）空肠白蛋白丢失和有碳标记的绒毛发生率在最初30分钟内增加，此后前者逐渐下降，而后者保持在平台期。这些发现表明，绒毛核心收缩和淋巴管受压是乙醇诱导上皮损伤的主要原因，微血管通透性增加和随之而来的蛋白质渗漏会加剧这种损伤。尽管持续进行乙醇灌注，但大多数参数恢复的机制仍有待研究。
