Alterations in rabbit retina lipid metabolism induced by detachment. Decreased incorporation of [3H]DHA into phospholipids.
Alterations in rabbit retina lipid metabolism induced by detachment. Decreased incorporation of [3H]DHA into phospholipids.
复制标题
脱离引起的兔视网膜脂质代谢的改变。
DOI：
10.1007/bf00133731
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发表时间：
1995
影响因子：
1.6
通讯作者：
Bazan,NG
中科院分区：
文献类型：
--
作者：
Santos,FF;deTurco,EB;Gordon,WC;Peyman,GA;Bazan,NG
研究背景二十二碳六烯酸(22：6N-3，DHA)在视网膜膜磷脂中含量较高，对其功能起着至关重要的作用。本研究用[~3H]-DHA研究了视网膜脱离对体外脂代谢的影响。方法将生理盐水注入兔视网膜下腔，使视网膜脱离视网膜色素上皮。对照组(未手术)和假手术(手术，未脱离)动物的视网膜标本，以及同眼视网膜附着和脱离区域的标本，在体外与[~3H]DHA孵育4h，然后准备进行生化和放射自显影分析。结果在对照和假视网膜中，[~3H]DHA优先被酯化为磷脂(82%)和低标记的游离脂肪酸(FFA)(5%)。在视网膜分离区域的样品中，在FFA池中回收了较高比例的[~3H]DHA(高达30%)，其酯化反应被分流到三酰甘油，从而减少了[~3H]DHA-磷脂的形成。这些变化在脱离后48小时内保持不变。放射自显影显示对照组视网膜内节和突触终末有较高的标记，而在脱离的视网膜中，神经视网膜有大量标记，并最终位于光感受器层内。结论视网膜脱离可导致脂代谢的长期改变，这种改变反映在[3 H]DHA磷脂标记的降低。持续48小时的代谢变化可能导致磷脂的合成/周转不足，其中含有DHA的磷脂可能导致视盘膜组装缺陷，继而导致视觉细胞的恶化。
BackgroundDocosahexaenoic acid (22 ∶ 6n-3, DHA) is found in high concentration in phospholipids from retinal membranes, and is essential for their function. This study investigated the effect of in vivo retinal detachment on in vitro lipid metabolism using [3H]DHA.MethodsRabbit retina was detached from the retinal pigment epithelium by injecting physiological saline into the subretinal space of the eye. Retinal samples from control (non-operated) and sham (operated, no detachment) animals, and from attached and detached retinal areas from the same eye, were incubated in vitro with [3H]DHA for 4 hours, and then prepared for biochemical and autoradiographic analysis.ResultsIn control and sham retinas, [3H]DHA was preferentially esterified into phospholipids (82%) with low labeling of free fatty acids (FFA) (5%). In samples from detached areas of the retina, a higher proportion of [3H]DHA was recovered in the FFA pool (up to 30%) and its esterification was shunted into triacylglycerol, thereby reducing the formation of [3H]DHA-phospholipids. Changes were sustained through 48 hours of postdetachment. High labeling of inner segments and synaptic terminals was observed autoradiographically in control retinas, while in detached retinas, clusters of labeling were detected in the neural retina, and eventually within the photoreceptor layer.ConclusionRetinal detachment induces longlasting changes in lipid metabolism which are reflected in lower labeling of [3H]DHA-phospholipids. Metabolic changes, sustained through 48 hours, may lead to inadequate synthesis/turnover of phospholipids, among them, those containing DHA, possibly resulting in defective disc membrane assembly with subsequent deterioration of visual cells.