Yoshida M, Roth R I, Grunfeld C, Feingold K R, Levin J
Department of Laboratory Medicine, University of California School of Medicine, San Francisco, USA.
J Lab Clin Med. 1996 Jul;128(1):103-14. doi: 10.1016/s0022-2143(96)90119-5.
(1-->3)-beta-D-glucan is a ubiquitous constituent of fungi, and elevated plasma glucan levels are commonly present in patients with deep mycosis or fungemia. The pharmacokinetics, biologic effects, and distribution in blood and organs of iodine 125-labeled (1--> 3)-beta-D-glucan purified from Candida albicans organisms were analyzed in rabbits during the 24-hour period after intravenous administration of this constituent. The intravascular half-life of beta-glucan was 1.8 minutes in the low-dose group (9.3 micrograms/kg, n = 3) and 1.4 minutes in the high-dose group (222 micrograms/kg, n = 3), and the total body clearance was 1.12 +/- 0.30 ml/min and 1.17 +/- 0.16 ml/min (mean +/- SD), respectively (not significantly different). The serum concentration of (1-->3)-beta-D-glucan was also biologically determined by a test using coagulation factor G of the Japanese horse-shoe crab (G test). There was good correlation between the clearance of beta-glucan measured biologically and isotopically. During the 24-hour period of observation the rabbits remained well and beta-glucan failed to alter blood cell counts, tumor necrosis factor levels, or lipid metabolism. 125I-labeled beta-glucan associated with the blood cellular compartment initially was less than 3% (the majority in the platelets) and decreased further during the following 2-hour period. Over 97% of circulating 125I-labeled beta-glucan was associated with the cell-free plasma, and the majority of this glucan in plasma appeared not to be associated with lipoproteins. The liver contained more than 80% of the 125I-labeled beta-glucan detected in the six major organs analyzed.
（1→3）-β-D-葡聚糖是真菌普遍存在的一种成分，深部真菌病或真菌血症患者血浆葡聚糖水平通常会升高。对从白色念珠菌中纯化得到的碘125标记的（1→3）-β-D-葡聚糖，在静脉注射给家兔后的24小时内，分析其药代动力学、生物学效应以及在血液和器官中的分布情况。低剂量组（9.3微克/千克，n = 3）中β-葡聚糖的血管内半衰期为1.8分钟，高剂量组（222微克/千克，n = 3）为1.4分钟，全身清除率分别为1.12±0.30毫升/分钟和1.17±0.16毫升/分钟（均值±标准差），二者无显著差异。（1→3）-β-D-葡聚糖的血清浓度也通过使用日本鲎凝血因子G的试验（G试验）进行生物学测定。生物学测定的β-葡聚糖清除率与同位素测定的清除率之间具有良好的相关性。在观察的24小时内，家兔状态良好，β-葡聚糖未改变血细胞计数、肿瘤坏死因子水平或脂质代谢。最初与血细胞部分结合的125I标记的β-葡聚糖不到3%（大部分在血小板中），并在随后的2小时内进一步减少。超过97%的循环125I标记的β-葡聚糖与无细胞血浆结合，血浆中大部分这种葡聚糖似乎与脂蛋白无关。在所分析的六个主要器官中，肝脏含有超过80%检测到的125I标记的β-葡聚糖。
