Effects of aspirin on mesenteric lymph nodes of rabbits as basis for its use on lymph nodes metastases.

PURPOSE To evaluate the effects of aspirin 10% and 20% on mesenteric lymph nodes of rabbits as basis for its use on lymph nodes metastases. METHODS A total of 20 lymph nodes from 20 rabbits (randomized in four groups) were evaluated. Aspirin solutions 10% (groups A and C) and 20% (groups B and D) were injected into mesenteric lymph nodes of healthy rabbits and had its gross and histological effects evaluated at 24 hours (groups A and B) and at seven days (groups C and D). RESULTS In the groups A and B evaluated at 24 hours it was observed extensive necrosis and hemorrhage, a significant increase in apoptosis throughout the lymph node with medullary sinuses enlargement and an increase in germinal centers. In the groups C and D evaluated at seven days of solution injection there was also an increase in apoptosis with higher elevation of histiocytes and a significant decrease of necrosis and an increase of giant cells was noticed causing a foreign body chronic inflammation. In all comparisons, there were no differences between the concentrations used (10 and 20%). CONCLUSIONS The injection of aspirin on lymph nodes caused necrosis and an increase of apoptosis after 24 hours and after seven days of treatment there was regeneration of the lymph nodes, with intense decrease of necrosis and a great elevation of apoptosis. These experimental results support future clinical studies on application of aspirin in the treatment of lymphatic metastases, since the increase of apoptosis is one of the pillars of cancer therapy.