PHOSPHOLIPID ASYMMETRY IN CARDIAC SARCOLEMMA - ANALYSIS OF INTACT-CELLS AND GAS-DISSECTED MEMBRANES
PHOSPHOLIPID ASYMMETRY IN CARDIAC SARCOLEMMA - ANALYSIS OF INTACT-CELLS AND GAS-DISSECTED MEMBRANES
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DOI：
10.1016/0005-2736(88)90557-3
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发表时间：
1988-08-18
期刊：
影响因子：
--
通讯作者：
VERKLEIJ, AJ
中科院分区：
文献类型：
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作者：
POST, JA;LANGER, GA;VERKLEIJ, AJ
研究了培养的新生大鼠心脏细胞肌膜的磷脂组成及磷脂类在两层肌膜之间的分布。质膜经“气体解剖”技术分离得到细胞总磷脂的38%存在于肌膜中，其组成为：磷脂酰乙醇胺（PE） 24.9%，磷脂酰胆碱（PC） 52.0%，磷脂酰丝氨酸/磷脂酰肌醇（PS/PI） 7.2%，鞘磷脂13.5%。肌膜的胆固醇/磷脂比值为0.5。利用磷脂酶A2、鞘磷脂酶C或三硝基苯磺酸作为全细胞脂质膜探针，确定磷脂在内层和外单层之间的分布。探针可以接触到整个肌层表面，不会产生可检测到的细胞裂解。磷脂类分布不对称：(1)带负电荷的磷脂，PS/PI仅位于内小叶或细胞质小叶中；(2)75%的PE位于内小叶；(3)鞘磷脂93%位于外小叶；(4) 43%的PC在外页。从磷脂-离子结合关系、磷脂与离子的交换和转运以及心肌细胞对缺血-再灌注的反应等方面讨论了磷脂/PI和PE在细胞质肌层表面的优势。
The investigation focuses on the phospholipid composition of the sarcolemma of cultured neonatal rat heart cells and on the distribution of the phospholipid classes between the two monolayers of the sarcolemma. The plasma membranes are isolated by ''gas-dissection'' technique and 38% of total cellular phospholipid is present in the sarcolemma with the composition: phosphatidylethanolamine (PE) 24.9%, phosphatidylcholine (PC) 52.0%, phosphatidylserine/phosphatidylinositol (PS/PI) 7.2%, sphingomyelin 13.5%. The cholesterol/phospholipid ratio of the sarcolemma is 0.5. The distribution of the phospholipids between inner and outer monolayer is defined with the use of two phospholipases A2, sphingomyelinase C or trinitrobenzene sulfonic acid as lipid membrane probes in whole cells. The probes have access to the entire sarcolemmal surface and do not produce detectable cells lysis. The phospholipid classes are asymmetrically distributed: (1) the negatively charged phospholipids, PS/PI are located exclusively in the inner or cytoplsmic leaflet: (2) 75% of PE is the inner leaflet; (3) 93% of sphingomyelin is in the outer leaflet; (4) 43% of PC is in the outer leaflet. The predominance of PS/PI and PE at the cytoplasmic sarcolemmal surface is discussed with respect to phospholipid-ionic binding relations between phospholipids and exchange and transport of ions and the response of the cardiac cell on ischemia-reperfusion.