HEALTH-Institute for Biomedicine and Health Sciences, Joanneum Research Forschungsgesellschaft m.b.H, Neue Stiftingtalstrasse 2, 8010 Graz, Austria.
Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
Biomed Phys Eng Express. 2021 Apr 12;6(6):065031. doi: 10.1088/2057-1976/abc3a7.
To implement OFM-recirculation and OFM-suction capable of direct and absolute in-vivo quantification of albumin in the ISF of pigs.
OFM-recirculation and OFM-suction were used to collect ISF in-vivo in pigs and lymph was collected from the same pigs after OFM sampling. Blood was collected before and after OFM sampling, plasma was isolated and mean albumin plasma concentrations per pig were used to yield albumin ISF-to-plasma ratios. We characterized the quality of the collected undiluted ISF via (1) stable albumin ISF-to-plasma ratio in OFM-recirculation and in OFM-suction samples, (2) comparison of albumin ISF-to-plasma ratios from OFM-recirculation and OFM-suction and (3) comparison of normalized albumin concentrations in the ISF and lymph.
Both advanced OFM methods were successfully implemented and albumin was quantified from the collected ISF samples. OFM-recirculation reached stable albumin ISF-to-plasma ratios after 20 recirculation cycles. Absolute ISF albumin concentrations were 11.2 mg ml (OFM-recirculation) and 14.2 mg ml (OFM-suction). Albumin ISF-to-plasma ratios were 0.39 ± 0.04 (OFM -recirculation) and 0.47 ± 0.1 (OFM-suction).
Knowledge of the ISF protein content is of major importance when assessing PK/PD effects, especially of highly protein bound drugs. Up to now, only blood albumin values have been available to determine the degree of protein binding in several tissues. OFM-recirculation and OFM-suction allow direct, absolute quantification of albumin in ISF for the first time and enable investigation of the degree of protein binding of a drug directly in its target tissue.
实现 OFM 再循环和 OFM 抽吸，以直接、绝对定量猪 ISF 中的白蛋白。
使用 OFM 再循环和 OFM 抽吸在猪体内采集 ISF，从同一头猪中采集淋巴。在 OFM 采样前后采集血液，分离血浆，并计算每头猪的平均白蛋白血浆浓度，以得出白蛋白 ISF 与血浆的比值。我们通过以下方法来表征采集的未稀释 ISF 的质量：（1）在 OFM 再循环和抽吸样本中，白蛋白 ISF 与血浆的比值稳定；（2）比较 OFM 再循环和抽吸的白蛋白 ISF 与血浆的比值；（3）比较 ISF 和淋巴中归一化的白蛋白浓度。
两种先进的 OFM 方法都成功实施，从采集的 ISF 样本中定量了白蛋白。OFM 再循环在 20 次再循环后达到稳定的白蛋白 ISF 与血浆的比值。绝对 ISF 白蛋白浓度为 11.2 mg/ml（OFM 再循环）和 14.2 mg/ml（OFM 抽吸）。白蛋白 ISF 与血浆的比值分别为 0.39±0.04（OFM 再循环）和 0.47±0.1（OFM 抽吸）。
在评估 PK/PD 效应时，了解 ISF 蛋白含量非常重要，特别是对于高度蛋白结合的药物。到目前为止，只有血液白蛋白值可用于确定几种组织中蛋白结合的程度。OFM 再循环和 OFM 抽吸首次允许直接、绝对定量 ISF 中的白蛋白，并能够直接在其靶组织中研究药物的蛋白结合程度。
