Leitch G J, Harris-Hooker S A, Udezulu I A
Department of Physiology, Morehouse School of Medicine, Atlanta, Georgia 30310.
Am J Trop Med Hyg. 1988 Sep;39(3):282-7. doi: 10.4269/ajtmh.1988.39.282.
Entamoeba histolytica trophozoites were centrifuged into mucus gels harvested from in vivo loops of rat cecum and proximal colon. Frank ameba movement was not detected in the colonic mucus, but attenuated motility was measured in the cecal mucus. The harvested rat cecal mucus had significantly lower apparent viscosity and neutral glycoprotein concentration values than the colonic mucus. A shape factor method was developed to assess the motility of amebae in mucus gels and intact mucus blankets. Shape factor data obtained from harvested mucus gel and intact mucus blanket experiments indicated that such mucus severely attenuated trophozoite movement with the attenuation being greater with colonic than with cecal mucus. Entamoeba trophozoites are known to be able to generate a pseudopod force of 3.3 x 10(-6) Newtons. Latex microspheres of the size range of Entamoeba trophozoites were forced through cecal and colonic mucus gels under gravity. Colonic mucus gels could withstand a force of 3.3 x 10(-6) Newtons while cecal mucus could not, suggesting that the ameba movement that was observed in cecal mucus involved mechanical penetration of the mucus by the ameba pseudopodia and did not require prior gel dissolution by Entamoeba enzymes.
将溶组织内阿米巴滋养体离心至从大鼠盲肠和近端结肠的体内肠袢收集的黏液凝胶中。在结肠黏液中未检测到明显的阿米巴运动，但在盲肠黏液中测得运动减弱。收集的大鼠盲肠黏液的表观粘度和中性糖蛋白浓度值明显低于结肠黏液。开发了一种形状因子方法来评估黏液凝胶和完整黏液层中阿米巴的运动。从收集的黏液凝胶和完整黏液层实验获得的形状因子数据表明，这种黏液严重减弱了滋养体的运动，结肠黏液的减弱作用比盲肠黏液更大。已知溶组织内阿米巴滋养体能够产生3.3×10⁻⁶牛顿的伪足力。在重力作用下，将溶组织内阿米巴滋养体大小范围的乳胶微球压过盲肠和结肠黏液凝胶。结肠黏液凝胶能够承受3.3×10⁻⁶牛顿的力，而盲肠黏液则不能，这表明在盲肠黏液中观察到的阿米巴运动涉及阿米巴伪足对黏液的机械穿透，并且不需要溶组织内阿米巴酶预先溶解凝胶。
