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Visualizing lymph movement in anuran amphibians with computed tomography (879.9)
Author(s) -
Hedrick Michael,
Hansen Kasper,
Wang Tobias,
Thygesen Jesper,
Pedersen Michael
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.879.9
Subject(s) - lymph , lymphatic system , anatomy , contrast medium , medicine , pathology , radiology
Lymph flux rates in anuran amphibians are high relative to other vertebrates owing to ‘leaky’ capillaries and a very high interstitial compliance. Lymph movement is accomplished primarily by specialized lymph muscles and lung ventilation that move lymph through interconnected lymph sacs to the dorsally‐located lymph hearts which are responsible for pumping lymph back into the circulatory system. The highly compartmentalized lymph sacs have been described anatomically, but it is unclear how lymph moves through the lymphatic system to the lymph hearts. We used computed tomography (CT) to visualize an iodinated contrast solution, injected into various lymph sacs, through the lymph system in awake cane toads ( Rhinella marina ). Toads were anesthetized with MS‐222 and small bore cannulae (PE 50) were placed into a variety of lymph sacs(subvertebral, lateral, interfemoral, brachial, crural) to inject contrast solution (0.25‐1.0 ml; Visipaque TM 320 mg I/ml). Isotropic 0.216 mm 3 /voxel CT scans were acquired with a 64‐Slice Siemens Somatom Definition (Siemens Medical Solutions, Germany) at 80 kV, tube current 273 mA. Scanning time was approximately 12 seconds and scans were performed repeatedly for 1 min to 180 min following injection of the contrast solution. CT‐data was analyzed qualitatively in the 3D viewer in Osirix‐software where movement of the contrast was clearly visible over time, although clearance rates differed considerably between lymph sacs. We observed vertical movement of contrast in lateral and interfemoral sacs as predicted from previous studies. A surprising result was the observation of a previously undescribed pathway for lymph movement from the subvertebral sac ventrally between the lungs. These visual results confirm predictions about the movement of lymph, but also provide some novel findings regarding the pathways for lymph movement. Grant Funding Source : Supported by the National Science Foundation and the Danish Research Council