Ramsammy L, Ling K Y, Josepovitz C, Levine R, Kaloyanides G J
Biochem Pharmacol. 1985 Nov 1;34(21):3895-900. doi: 10.1016/0006-2952(85)90441-1.
We examined the hypothesis that lipid peroxidation participates in the pathogenesis of aminoglycoside-induced nephrotoxicity. Male Sprague-Dawley rats were injected subcutaneously with gentamicin, 100 mg/kg per day, for 1-4 days. Twenty-four or forty-eight hours after the last injection the rats were killed and the renal cortex was processed for total phospholipids, malondialdehyde (MDA), phospholipid fatty acid composition, superoxide dismutase, catalase and glutathione. Gentamicin induced a significant increase in total renal cortical phospholipids which was evident after a single injection and by the third injection reached a plateau 17% above the baseline level. MDA, an end product of lipid peroxidation, increased from 0.674 +/- 0.021 nmole/mg protein in the control group to 0.931 +/- 0.053 nmole/mg protein (P less than 0.001) 48 hr after the fourth injection. As another index of lipid peroxidation, we determined the shift from polyunsaturated to saturated fatty acids of renal cortical phospholipids. By the second injection of gentamicin we detected a significant decline of arachidonic acid (20:4) present in phospholipid. By the fourth injection, arachidonic acid had fallen 48% below control and was accompanied by reciprocal increases of more saturated fatty acids including linoleic (18:2), oleic (18:1) and palmitic (16:0) acids. The number of double bonds per mole of fatty acid declined from a baseline value of 1.62 +/- 0.01 to 1.20 +/- 0.02 (P less than 0.001) by the fourth injection of drug. Superoxide dismutase showed no consistent alteration, whereas catalase activity (k) fell from the control value of 0.221 +/- 0.007 min to 0.155 +/- 0.009 min (P less than 0.01) by the third injection, where k is the first-order rate constant. Total and reduced glutathione declined after the fourth injection of gentamicin accompanied by a shift to oxidized glutathione with an increase in the ratio of oxidized to total glutathione. These data support the conclusion that accelerated lipid peroxidation occurs early in the course of gentamicin administration and raise the possibility that lipid peroxidation is a proximal event in the injury cascade of gentamicin nephrotoxicity.
我们检验了脂质过氧化参与氨基糖苷类药物所致肾毒性发病机制的假说。将雄性Sprague-Dawley大鼠皮下注射庆大霉素，剂量为每天100mg/kg，持续1 - 4天。在最后一次注射后24小时或48小时处死大鼠，取肾皮质检测总磷脂、丙二醛（MDA）、磷脂脂肪酸组成、超氧化物歧化酶、过氧化氢酶和谷胱甘肽。庆大霉素使肾皮质总磷脂显著增加，单次注射后即明显，第三次注射时达到平台期，比基线水平高17%。脂质过氧化的终产物MDA，在第四次注射后48小时，从对照组的0.674±0.021nmol/mg蛋白增加至0.931±0.053nmol/mg蛋白（P＜0.001）。作为脂质过氧化的另一指标，我们测定了肾皮质磷脂中多不饱和脂肪酸向饱和脂肪酸的转变。第二次注射庆大霉素后，我们检测到磷脂中花生四烯酸（20:4）显著下降。第四次注射时，花生四烯酸比对照下降了48%，同时包括亚油酸（18:2）、油酸（18:1）和棕榈酸（16:0）在内的更饱和脂肪酸相应增加。每摩尔脂肪酸的双键数在第四次注射药物后从基线值1.62±0.01降至1.20±0.02（P＜0.001）。超氧化物歧化酶无一致变化，而过氧化氢酶活性（k）在第三次注射时从对照组值0.221±0.007min降至0.155±0.009min（P＜0.01），这里k是一级速率常数。第四次注射庆大霉素后，总谷胱甘肽和还原型谷胱甘肽下降，同时向氧化型谷胱甘肽转变，氧化型与总谷胱甘肽的比值增加。这些数据支持以下结论：在庆大霉素给药过程早期发生了加速的脂质过氧化，并增加了脂质过氧化是庆大霉素肾毒性损伤级联反应中近端事件的可能性。
