Abstract
Purpose: :
To determine the size dependence and kinetics of the delivery of dextrans from the anterior chamber (AC) to the facial and cervical lymph nodes (fLNs, cLNs).
Methods: :
Anesthetized adult Long-Evans rats received monocular AC injections of a solution containing 8.3-ug each of 3kDa dextran-Cascade Blue, 40kDa dextran-Texas Red, and 500kDa dextran-FITC. The rats were exanguinated 2, 4, 6, 12, 24, and 72 hours later, and the eyes, fLNs, and cLNs were isolated. Each tissue sample was homogenized in saline and total content of each dextran type was determined by spectrofluorometry. Separate rats received AC injection of 15-ug 40kDa-lysine fixable dextran-FITC. Lymph nodes from these rats were examined histologically at 4 and 24 hrs after the injection.
Results: :
Residual dextran of each type washed out of the injected eyes by 12-72 hours after the injection (see Table). There was no recovery of 3kDa dextran in either fLNs or cLNs. There was greater recovery of 40kDa dextran than the 500kDa dextran in both lymph node types (P<0.05). Histology showed 40kDa dextran was contained within lymph node cells at both 4 and 24 hours post injection.
Conclusions: :
Transport of 40kDa dextran from the AC to the fLN and cLN is more efficient than 500kDa dextran. In contrast, there is negligible transport of 3kDa dextran. These results are consistent with the known uptake characteristics for soluble molecules by lymphatic vessels. Hence, they support the view that large macromolecules from the AC are taken up and transported by lymphatic vessels to the fLN and cLN.
Keywords: anterior chamber • aqueous • outflow: ciliary muscle