LIPID AND CARBOHYDRATE-METABOLISM OF GIARDIA-LAMBLIA
LIPID AND CARBOHYDRATE-METABOLISM OF GIARDIA-LAMBLIA
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DOI：
10.1016/0166-6851(81)90099-2
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发表时间：
1981-01-01
影响因子：
1.5
通讯作者：
MORSE, SA
中科院分区：
文献类型：
--
作者：
JARROLL, EL;MULLER, PJ;MORSE, SA
利用从人体内分离的滋养体和体外培养的含有胎牛血清的培养基，研究了兰氏螺旋体的脂质和碳水化合物代谢。蓝氏滋养体的磷脂、脂肪酸和中性脂组成与培养基相似。磷脂酰乙醇胺、磷脂酰胆碱和鞘磷脂是检测到的主要磷脂；单酰基、二酰基、三酰基甘油酯、甾醇和甾酯是发现的主要中性脂类。还检测到几种未确定的糖脂。葡萄糖和苏氨酸很容易被滋养体吸收，但不能被细胞磷脂或固醇吸收。大约86%的葡萄糖被并入滋养体，在核酸中发现，38%的苏氨酸被并入细胞蛋白中。将少量葡萄糖和苏氨酸掺入到含糖脂的馏分中。滋养体中没有明显的甘油和醋酸盐掺入，而3-磷酸甘油掺入未检测到。胆固醇很容易被滋养体吸收；其中98%是在甾醇部分中发现的。放射性肺活量测定数据表明，兰氏螺旋体葡萄糖代谢的主要途径是通过Embden-Meyerhof-Parnas途径和戊糖磷酸途径。葡萄糖代谢过程中形成的内源性醋酸酯（如乙酰辅酶a）不用于脂质生物合成。兰氏滋养体显然不能重新合成细胞磷脂或甾醇，而是使用培养基中已经存在的脂质。
The lipid and carbohydrate metabolism of G. lamblia was studied using trophozoites isolated from a human and axenically grown in vitro in medium containing fetal bovine serum. The phospholipid, fatty acid and neutral lipid composition of the G. lamblia trophozoites was similar to that of the medium. Phosphatidylethanolamine, phosphatidylcholine and sphingomyelin were the major phospholipids detected; monoacyl-, diacyl-, triacylglycerides, sterols and sterol esters were the major neutral lipids found. Several unidentified glycolipids were also detected. Glucose and threonine were readily incorporated by the trophozoites but not into cellular phospholipids or sterols. Approximately 86% of the glucose incorporated into the trophozoites was found in the nucleic acids and 38% of the threonine incorporated was detected in the cellular proteins. Small amounts of the glucose and threonine were incorporated into glycolipid-containing fractions. Glycerol and acetate were not appreciably incorporated into trophozoites while glycerol 3-phosphate incorporation was not detected. Cholesterol was readily assimilated by the trophozoites; 98% of that incorporated was found in the sterol fraction. Radiorespirometric data suggest that the major routes of glucose metabolism in G. lamblia are via Embden-Meyerhof-Parnas and pentose phosphate pathways. Endogenous acetate (as acetyl-CoA) formed during the metabolism of glucose is not used for lipid biosynthesis. G. lamblia trophozoites are evidently incapable of synthesizing cellular phospholipids or sterols de novo but rather use lipids already present in the medium.