Ustenko Zh., Gushchin Ya. Methods of visualization of rat lymphatic vessels and nodes. Laboratory Animals for Science. 2020; 4. https://doi.org/10.29296/2618723X-2020-04-06
Тhe lymphatic system of animals and humans consists of lymph, lymphatic capillaries, vessels, ducts and lymphatic organs. It drainage and detoxification functions, and plays an important role in the formation of the immune response and metastasis processes. In the literature, the structure and topography of the lymph nodes are comprehensively described, but little attention is paid to the lymphatic pathways. The study of the lymphatic system is difficult on animal-biological models. Some of its components are difficult to identify. The lymphatic vessels are difficult to detect on macroscopic examination, even in large animals, since the lymphatic vessel wall is thin and the lymph is colorless. The lymph nodes in small rodents are difficult to study because of its small size. In addition, the lymph node tissue may not contrast well with the surrounding fatty tissue. The combination of these factors can lead to inaccuracies during the sampling and cutting of material. This article presents techniques for visualizing lymphatic vessels and lymph nodes in rats. We visualized the lymphatic vessels by subcutaneous injections of hydrogen peroxide, tinted with ink or acrylic blue paint. There was observed coloration of lymphatic vessels and regional lymph nodes in both cases. We injected the dye solution to animals immediately after death, after 2, 4, 12 and 24 hours. There was observed coloration of lymphatic vessels and regional lymph nodes in all corpses that’s been in storage for 2-24 hours, and only in one fresh corpse. The best visualization of the lymphatic vessels by this method was achieved in the limbs and tail. We were unable to reach reproducible results in the head, neck and trunk with this technique. We sampled for histological analysis lymphatic vessels painted ink. There was observed the coloration of the epithelium of the lymphatic vessel in one case. We visualized the lymph nodes by fixation in Davidson's solution for 2 and 19 hours. The use of this method provided better visualization of the lymph nodes during cutting compared with visualization after 10% formalin fixation. In addition, fixation in Davidson's solution has provided better detailing of the lymphoid cell nuclei.
Autors’ contributions
Ustenko Zh. – conducting research, systematization materials, writing the article, editing the article, providing of the photo materials.
Gushchin Ya. – idea, concept and design of the research, editing the article.