Embaye H, Whybrew L, Odedra R M, Hart C A, Fletcher J N, Saunders J R, Batt R M
Department of Small Animal Medicine, Royal Veterinary College, University of London, North Mymms, Hertfordshire.
Res Vet Sci. 1995 Jul;59(1):50-5. doi: 10.1016/0034-5288(95)90030-6.
The effects of pokeweed lectin (PWL) and concanavalin A (Con A) on microvillar membrane (MVM) proteins during the organ culture of rabbit ileal explants for 24 hours were compared with the known effects of enteropathogenic Escherichia coli (EPEC). PWL resulted in the accelerated release of brush border enzymes into the culture medium, accompanied by decreased tissue activities and an increase in the total activity present in the tissue and culture medium. Con A had less effect on the release and tissue activities of brush border enzymes and the total activity was not increased. Sucrose density gradient centrifugation of the culture medium showed that MVM enzymes were predominantly particulate, consistent with their release as vesicles. Centrifugation of ileal explants showed that PWL, but not Con A, resulted in a decrease in the modal density of the brush border which was consistent with a lower glycoprotein-to-lipid ratio. These findings suggest that PWL, in common with EPEC, may cause the disruption and vesiculation of microvilli and the compensatory stimulation of MVM protein synthesis.
将商陆凝集素（PWL）和刀豆球蛋白A（Con A）对兔回肠外植体进行24小时器官培养期间微绒毛膜（MVM）蛋白的影响，与肠致病性大肠杆菌（EPEC）的已知影响进行了比较。PWL导致刷状缘酶加速释放到培养基中，同时组织活性降低，而组织和培养基中的总活性增加。Con A对刷状缘酶的释放和组织活性影响较小，总活性没有增加。对培养基进行蔗糖密度梯度离心显示，MVM酶主要为颗粒状，这与其以囊泡形式释放一致。对回肠外植体进行离心显示，PWL而非Con A导致刷状缘的模态密度降低，这与较低的糖蛋白与脂质比率一致。这些发现表明，PWL与EPEC一样，可能导致微绒毛的破坏和囊泡化以及MVM蛋白合成的代偿性刺激。
