Measurement of the fractional uptake of macromolecules by the renal vascular bed compared to other vascular beds.
Measurement of the fractional uptake of macromolecules by the renal vascular bed compared to other vascular beds.
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与其他血管床相比，测量肾血管床对大分子的摄取分数。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
G. Rodey
中科院分区：
文献类型：
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作者：
L. Hebert;K. A. Stuart;C. Allhiser;G. Rodey
类似可溶性免疫复合物的大分子可以由热聚集的人γ球蛋白（AHGG）制成。在15只大鼠中，我们研究了125i标记的AHGG (AHGG)-125I持续静脉注射超过1小时的血管捕获，同时通过间歇性地在主动脉弓注射85sr标记的微球来标记组织血流量。同时注入带有51Cr标记的红细胞（RBC-51Cr），以便在实验结束时切除组织时，计算每个组织标本的血管体积，以纠正AHGG-125I的125I问题，AHGG-125I在切除组织时没有被捕获，只是在基底间隙中运输。这些数据使我们能够计算AHGG-125I （FM）在给定组织中的吸收分数，并与任何其他组织进行比较。我们选择将各组织的FM与肾皮质的FM进行比较。这种比较被表示为一个比率称为FM比率为给定的组织。以下组织的FM比值显著大于1.00（即单位血流量，这些组织比肾皮质更强烈地捕获AHGG-125I）：肝、脾、皮肤、胃、脂肪、睾丸和大肠。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 （p均小于0.025）。肾上腺、心脏、胸腺和膈肌的FM比值与1.00无显著差异。肺和脑的FM比值分别为0.014 +/- 0.008和0.14 +/- 0.065，均显著小于1.00 （p < 0.001）。在13个实验中，肾小球的回收率为23.8% +/- 3.5%，这是通过肾皮质中含有的微球的回收率来评估的。与整个肾皮质相比，离体肾小球只含有少量的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。从每单位递送速率捕获复合物的量来看，许多器官比肾皮质更容易捕获AHGG-125I。此外，在目前的实验条件下，肾小球不是大分子摄取的主要肾内部位。
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.