Hebert L A, Stuart K A, Allhiser C, Rodey G E
J Lab Clin Med. 1976 Nov;88(5):716-24716-24.
Macromolecules resembling soluble immune complexes can be made from heat-aggregated human gamma globulin (AHGG). In 15 rats, we studied vascular trapping of 125I-labeled AHGG (AHGG)-125I) given by constant I.V. infusion over 1 hour while tissue blood flow was marked by intermittant aortic arch injections of 85Sr-labeled microspheres. Red cells labeled with 51Cr (RBC-51Cr) were also infused so that when the tissues were removed at the end of the experiment, the vascular volume of each tissue specimen could be balculated to correct issue 125I for AHGG-125I which was not trapped but simply in transit in the bascular space at the time the tissue was removed. These data permitted us to calculate the fractional uptake of AHGG-125I (FM) for a given tissue in comparison to any other tissue. We chose to compared the FM of each tissue to the FM of renal cortex. This comparison was expressed as a ratio termed the FM ratio for the given tissue. The following tissues had FM ratios significantly greater than 1.00 (i.e., per unit blood flow, these tissues trapped AHGG-125I more avidly than renal cortex): liver, spleen, skin, stomach, fat, testes, and large bowel. The respective ratios were 381 +/- 74, 15.7 +/- 4.0, 11.8 +/- 4.0, 7.47 +/- 1.95, 6.24 +/- 1.0 +/-, 3.03 +/- 0.67, 2.86 +/- 0.72 (all p less than 0.025). The FM ratio for adrenal, heart, thymus, and diaphragm were not significantly different from 1.00. The FM ratio of lung and brain were significantly less than 1.00: 0.014 +/- 0.008 and 0.14 +/- 0.065, respectively (p less than 0.001 for both). In 13 experiments, glomeruli was 23.8 +/- 3.5 per cent as assessed by recovery of the microspheres contained in renal cortex. Compared to whole renal cortex, the isolated glomeruli contained only minor amounts of AHGG-125I. We conclude that tissues vary widely with respect to their ability to trap macromolecules. When uptake is viewed in terms of the amount of complex trapped per unit delivery rate, many organs trap AHGG-125I for more avidly than renal cortex. Furthermore, under the present experimental conditions, glomeruli are not the major intrarenal site of macromolecule uptake.
类似于可溶性免疫复合物的大分子可由热聚集的人γ球蛋白（AHGG）制成。在15只大鼠中，我们研究了通过1小时持续静脉输注给予的125I标记的AHGG（AHGG-125I）的血管捕获情况，同时通过间歇性主动脉弓注射85Sr标记的微球来标记组织血流。还输注了用51Cr标记的红细胞（RBC-51Cr），以便在实验结束时取出组织时，能够计算每个组织标本的血管容量，以校正AHGG-125I在组织取出时未被捕获而是仅在血管空间中流动的情况。这些数据使我们能够计算给定组织中AHGG-125I的摄取分数（FM），并与任何其他组织进行比较。我们选择将每个组织的FM与肾皮质的FM进行比较。这种比较以给定组织的FM比表示。以下组织的FM比显著大于1.00（即，每单位血流，这些组织比肾皮质更 avidly地捕获AHGG-125I）：肝脏、脾脏、皮肤、胃、脂肪、睾丸和大肠。各自的比值分别为381±74、15.7±4.0、11.8±4.0、7.47±1.95、6.24±1.0 +/ -、3.03±0.67、2.86±0.72（所有p均小于0.025）。肾上腺、心脏、胸腺和膈肌的FM比与1.00无显著差异。肺和脑的FM比显著小于1.00：分别为0.014±0.008和0.14±0.065（两者p均小于0.001）。在13个实验中，通过肾皮质中包含的微球回收率评估，肾小球为23.8±3.5%。与整个肾皮质相比，分离的肾小球仅含有少量的AHGG-125I。我们得出结论，组织在捕获大分子的能力方面差异很大。当从每单位输送速率捕获的复合物量来看摄取时，许多器官比肾皮质更 avidly地捕获AHGG-125I。此外，在当前实验条件下，肾小球不是肾内大分子摄取的主要部位。
