Figure 4:

A. Fluorescence micrograph (Left) of rat synovium with 543 nm excitation (red, Texas red) and 488 nm excitation of muscle autofluorescence (green). Greyscale image (Right) showing trans-synovial transport of fluorescently-labeled dextrans. Bright fluorescence was typically observed at the synovial intima (most superficial part of the synovium) with decreasing fluorescence in the direction of transport towards the sub-synovium (scale bar = 100 μm). B. NF_s values for 10 kDa dextran transport across naive and MMT joint synovium following intra-articular injection. Decreasing NF_s is observed with distance from the synovial intima. C. NF_s values for 500 kDa dextran transport across joint synovium as described above. An exponential profile is observed with decreasing NF_s with distance from the synovium surface. The fluorescence profile for the 500 kDa dextran measured at 2h post-injection differed from that at 24h post-injection, for the naïve joints only (ANCOVA, p< 0.0001, not shown). The fluorescence profile did not differ with time for 10 kDa dextrans in any joint, nor for 500 kDa dextrans in the MMT joints. Data represent mean ± SD.