Minimally invasive quantification of lymph flow in mice and rats by imaging depot clearance of near-infrared albumin
| Autor: | Helge Wiig, Maja Mujic, Emmet McCormack, Olav Tenstad, Tine V. Karlsen |
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| Rok vydání: | 2011 |
| Předmět: |
Pathology
medicine.medical_specialty Physiology Depot Lymphatic System Mice Optical imaging Physiology (medical) Albumins Medicine Animals Fluorescent Dyes business.industry Albumin medicine.disease Pathophysiology Rats Lymphedema Lymphatic system Lymph flow Female Lymph Lymphatic function Radiopharmaceuticals Cardiology and Cardiovascular Medicine business |
| Zdroj: | American journal of physiology. Heart and circulatory physiology. 302(2) |
| ISSN: | 1522-1539 |
| Popis: | There is a lack of available methods to noninvasively quantify lymphatic function in small experimental animals, a necessity for studies on lymphatic system pathophysiology. We present a new method to quantify lymph flow in mice and rats, based on optically monitoring the depot clearance of near-infrared fluorescently labeled albumin and subsequent calculation of removal rate constants ( k). BSA was conjugated with Alexa680 NHS ester and remained stable in protein-rich solutions without free dye dissociation. To assess lymph flow, mice or rats were imaged every 30 or 60 min during a 3- to 6-h period following an intradermal injection of 0.5 or 1 μl Alexa680-albumin. Mice were awake between measurements, whereas rats were anesthetized throughout the experiment. The k, a parameter defined as equivalent to lymph flow, was calculated from the slopes of the resultant log-linear washout curves and averaged −0.40 ± 0.03 and −0.30 ± 0.02%/min for control C57BL/6 and C3H mice, respectively. Local administration of the vasoconstrictor endothelin-1 in mice led to a significant reduction in k, whereas overhydration in rats increased k, reflecting the coupling between capillary filtration and lymph flow. Furthermore, k was 50% of wild type in lymphedema Chy mice where dermal lymphatics are absent. We conclude that lymph flow can be determined as its rate constant k by optical imaging of depot clearance of submicroliter amounts of Alexa680-albumin. The method offers a minimally invasive, reproducible, and simple alternative to assess lymphatic function in mice and rats. |
| Databáze: | OpenAIRE |
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