| First Author | Karlsen TV | Year | 2012 |
| Journal | Am J Physiol Heart Circ Physiol | Volume | 302 |
| Issue | 2 | Pages | H391-401 |
| PubMed ID | 22101523 | Mgi Jnum | J:181796 |
| Mgi Id | MGI:5314188 | Doi | 10.1152/ajpheart.00842.2011 |
| Citation | Karlsen TV, et al. (2012) Minimally invasive quantification of lymph flow in mice and rats by imaging depot clearance of near-infrared albumin. Am J Physiol Heart Circ Physiol 302(2):H391-401 |
| abstractText | 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 mul 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. |
