Blais A, Morvan-Baleynaud J, Friedlander G, Le Grimellec C
Institut National de la Santé et de la Recherche Médicale U 251, Département de Physiologie, Faculté de Médecine Xavier Bichat, Paris, France.
Kidney Int. 1993 Jul;44(1):13-8. doi: 10.1038/ki.1993.206.
The effects of gentamicin treatment on functions of the plasma membrane-bound proteins in situ were investigated in primary culture of rabbit proximal tubular cells (PTC), a recognized model of renal epithelial cells. Activities of apical and basolateral enzymes, activities of phosphate, glucose and alanine sodium-coupled transport systems and leakage of the cytosolic enzyme lactate dehydrogenase (LDH) were determined in PTC grown in glucose-free culture medium as confluent monolayers and incubated with the aminoglycoside. Gentamicin altered in a concentration- and time-dependent manner the activity of dipeptidyl peptidase IV (DPP IV), neutral aminopeptidase (NAP), Na+K(+)-ATPase and the Vmax of sodium-dependent glucose and phosphate uptake, whereas gamma-glutamyl-transpeptidase (GGT) and sodium-dependent alanine uptake were unaffected. Identical concentration of gentamicin was required to induce LDH leakage and cell functions impairment. In contrast, under short time exposure, a condition where the enzyme activities were untouched, mercuric chloride inhibited to a similar extent the activity of the three sodium-coupled transport systems. These data suggest that whereas alterations in membrane fluidity might mediate the effects of gentamicin on membrane functions, the inhibition of transports by mercuric chloride rather reflects an effect on sodium permeability of the apical membrane. They also suggest that study of Na(+)-coupled transports in proximal tubular cells grown in primary culture is a simple and sensitive in vitro model to assess drug-induced nephrotoxicity.
在兔近端肾小管细胞（PTC）的原代培养中研究了庆大霉素处理对原位质膜结合蛋白功能的影响，PTC是公认的肾上皮细胞模型。在无葡萄糖培养基中生长至汇合单层并与氨基糖苷类药物孵育的PTC中，测定了顶端和基底外侧酶的活性、磷酸盐、葡萄糖和丙氨酸钠偶联转运系统的活性以及胞质酶乳酸脱氢酶（LDH）的泄漏情况。庆大霉素以浓度和时间依赖性方式改变二肽基肽酶IV（DPP IV）、中性氨基肽酶（NAP）、Na + K（+）-ATP酶的活性以及钠依赖性葡萄糖和磷酸盐摄取的Vmax，而γ-谷氨酰转肽酶（GGT）和钠依赖性丙氨酸摄取不受影响。诱导LDH泄漏和细胞功能损伤需要相同浓度的庆大霉素。相反，在短时间暴露下，即在酶活性未受影响的情况下，氯化汞对三种钠偶联转运系统的活性有类似程度的抑制作用。这些数据表明，膜流动性的改变可能介导庆大霉素对膜功能的影响，而氯化汞对转运的抑制作用更反映了对顶端膜钠通透性的影响。它们还表明，在原代培养中生长的近端肾小管细胞中研究钠偶联转运是评估药物诱导的肾毒性的一种简单而敏感的体外模型。
