[Structure and function of lymphatic capillaries in synovial joint]. / K struktúre a funkcii lymfatických kapilár v synoviálnom klbe.

The review article focuses on the structure and function of lymphatic capillaries in connective tissues of skin, muscles and synovial membrane. Lymphatic capillaries (initial lymphatics) are formed from endothelial cells mutually arranged so that their intercellular junctions have different structure. In one of the different types of intercellular junctions the distal ends of endothelial cells overlap one another in the form of projections. Desmosomes are missing between the cell membranes of the internal and external projection without presence of any other junctional complexes. The external projection of the endothelial cell is tightly attached to the surrounding connective tissue with the help of anchoring filaments. The internal projection of the neighbouring endothelial cell may tilt over to the lumen of the lymphatic capillary and this may result in a several micrometers wide communication between the interstitium and the lumen with efflux of tissue fluid and leukocytes from the interstitium in to the lumen of the capillary. Lymphologists call the above mentioned openable intercellular junctions in their works also endothelial microvalves or primary valves. These primary valves in cooperation with classical (secondary) intralymphatic valves enable one way lymph flow during spontaneous contractions of the initial lymphatics. It is supposed that primary valves in lymphatic capillaries have an important role in the drainage of the connective tissues affected by inflammation also in the synovial joint.

Treatment of rat adjuvant arthritis with flavonoid (Detralex), methotrexate, and their combination.

In both adjuvant arthritis and rheumatoid arthritis, edema and inflammation appear in synovial joints. Edema or effusion reflects an imbalance in lymph dynamics. Purified micronized flavonoid fraction is mainly used in the treatment of chronic venous insufficiency. This compound improves lymphatic drainage with a significant increase in lymphatic flow and lymphatic pulsality. It is suggested that the beneficial effect of purified micronized flavonoid fraction may be involved in the treatment of adjuvant arthritis in rats. In this study treatment of adjuvant arthritis in rats with Detralex, methotrexate, and their combination were evaluated. Groups of rats with adjuvant arthritis were treated with methotrexate (0.6 mg/kg/week), Detralex (20 mg/kg/day), and their combination for 50 days from adjuvant application. Hind paw swelling, arthrogram scores, serum albumin level, serum nitrite/nitrate concentrations, and whole-body mineral density were evaluated as markers of inflammation and destructive changes associated with arthritis. Long-term prophylactic treatment with low-dose methotrexate significantly inhibited the markers of both inflammation and arthritis. Detralex administered alone slightly decreased both the hind paw swelling and the arthritic score. Other inflammatory and arthritic markers were not significantly influenced. However, Detralex combined with methotrexate markedly potentiated the beneficial effects of methotrexate, which resulted in a more significant reduction in hind paw swelling, arthritic scores, and serum concentrations of nitrite/nitrate. Interestingly, the arthritis-induced decrease of bone mineral density in AA rats was significantly lower only in the group treated with the combination of Detralex and methotrexate. Our results indicate that Detralex increased the therapeutic efficacy of methotrexate basal treatment in AA. We suggest that this may be related to the beneficial effect of Detralex on microcirculation, especially on venules and lymphatic vessels.

Effects of purified micronized flavonoid fraction (Detralex) on prophylactic treatment of adjuvant arthritis with methotrexate in rats.

BACKGROUND: In both adjuvant arthritis and rheumatoid arthritis, edema and inflammation appear in synovial joints. Edema or effusion reflects an imbalance in lymph dynamics. Purified micronized flavonoid fraction is mainly used in the treatment of chronic venous insufficiency. This compound improves lymphatic drainage with a signicant increase in lymphatic flow and lymphatic pulsality. It is suggested that the beneficial effect of purified micronized flavonoid fraction may be involved in the treatment of adjuvant arthritis in rats. OBJECTIVES: To evaluate the effect of Detralex on methotrexate prophylactic treatment of adjuvant arthritis in rats. METHODS: Groups of rats with adjuvant arthritis were treated with methotrexate (0.6 mg/kg/week), Detralex (20 mg/kg/day) and their combination for 50 days from adjuvant application. Hind paw swelling, arthrogram scores, serum albumin level, serum nitrite/nitrate concentrations and whole body mineral density were evaluated as markers of inflammation and destructive changes associated with arthritis. RESULTS: Long-term prophylactic treatment with low dose methotrexate significantly inhibited the markers of both inflammation and arthritis. Detralex administered alone slightly decreased both the hind paw swelling and the arthritic score. Other inflammatory and arthritic markers were not significantly influenced. However, Detralex combined with methotrexate markedly potentiated the beneficial effects of methotrexate, which resulted in a more significant reduction in hind paw swelling, arthritic scores, and serum concentrations of nitrite/nitrate. Interestingly, the arthritis-induced decrease of BMD in AA rats was significantly lower only in the group treated with the combination of Detralex+methotrexate. CONCLUSION: Detralex increased the therapeutic efficacy of methotrexate basal treatment in AA. We suggest that this may be related to the beneficial effect of Detralex on microcirculation, especially on venules and lymphatic vessels.