Kiyomiya K, Matsushita N, Matsuo S, Kurebe M
Department of Toxicology, School of Veterinary Medicine, Osaka Prefecture University, Sakai, Japan.
J Vet Med Sci. 2000 Sep;62(9):971-5. doi: 10.1292/jvms.62.971.
Aminoglycoside antibiotics are generally accepted to accumulate in renal proximal tubule cells from the luminal surface and show toxic effects on the cells. The binding affinity and membrane permeability of aminoglycoside antibiotics are different at the brush border membrane (BBM) and the basolateral membrane (BLM) of proximal tubule cells. This study was performed, therefore, to investigate the differential effects of the aminoglycoside antibiotic gentamicin (GM) on cultured LLC-PK1 cells, a pig kidney proximal epithelial cell line, after addition to the BBM or the BLM side. LLC-PK1 cells were cultured on microporous membranes until forming confluent monolayers, and then GM was added to either the BBM or the BLM side. GM caused release of enzymes from the organelles, with a higher level of release observed following addition to the BBM side than that to the BLM side. Patterns of [3H]GM uptake by the cells differed in a manner dependent on whether it was added to the BBM or the BLM side. That is, the cellular uptake from the BBM side increased with incubation time, while that from the BLM side showed rapid saturation. These results suggested that aminoglycoside antibiotics show differential effects on cultured proximal epithelial cells and have differential patterns of cellular uptake when added to the BBM or the BLM side.
氨基糖苷类抗生素一般被认为是从管腔表面在肾近端小管细胞中蓄积，并对细胞产生毒性作用。氨基糖苷类抗生素在近端小管细胞的刷状缘膜（BBM）和基底外侧膜（BLM）处的结合亲和力和膜通透性有所不同。因此，本研究旨在探讨氨基糖苷类抗生素庆大霉素（GM）添加到BBM侧或BLM侧后，对猪肾近端上皮细胞系LLC-PK1培养细胞的不同影响。LLC-PK1细胞在微孔膜上培养直至形成汇合单层，然后将GM添加到BBM侧或BLM侧。GM导致细胞器释放酶，BBM侧添加后观察到的释放水平高于BLM侧。细胞对[3H]GM的摄取模式因添加到BBM侧还是BLM侧而有所不同。也就是说，从BBM侧的细胞摄取量随孵育时间增加，而从BLM侧的摄取量则迅速饱和。这些结果表明，氨基糖苷类抗生素对培养的近端上皮细胞表现出不同的影响，并且添加到BBM侧或BLM侧时具有不同的细胞摄取模式。
