Distribution of colloidal gold tracer within rat parasternal lymph nodes after intrapleural injection.

BACKGROUND: Tracer studies are an important tool to obtain information about the processes involved in the immunological response. Colloidal gold is widely used as a tracer, but its small size of label can cause some difficulty during low-resolution analysis. To overcome this difficulty, we developed a new method to follow the route of tracer movement within lymph nodes. METHODS: We applied conventional X-ray analysis, X-ray fluorescence analysis (XFA) subtractional microscopy using synchrotron radiation (SR) beams, light microscopy, and ultrastructural analysis to study the distribution and quantity of colloidal gold coupled with albumin within rat parasternal lymph node 2, 4, 6, 8, and 10 h after intrapleural injection of the tracer. RESULTS: At all the time points XFA-SR revealed that tracer formed a circle with a maximum concentration in the node periphery. XFA-SR measured colloidal gold concentration in the nodes reached its maximum (0.5-0.75 weight %) in 6-8 h. Subtractional microscopy revealed superficially located groups of cells filled with colloidal gold tracer. Light microscopy and ultrastructural analysis confirmed that the tracer was concentrated in the reticular cells, situated in the sinuses of the node. Sinusoidal reticular cells concentrated tracer at much higher rates than sinusoidal macrophages. Four hours after injection, gold appeared in the lysosomes of the follicular reticular cells. At the same time point, evidence of antigen presentation was obtained. Antigen presentation proved to be an extremely rara event since only one ultrastructural incident was found in 150 analysed grids. CONCLUSIONS: SR is a valuable tool for the analysis of gold tracer passage within the living organism.

[Roentgenologic investigation of collateral lymphatic pathways after ligation of the thoracic duct]. / Rentgenologicheskoe issledovanie kollateral'nykh limfaticheskikh putei posle pereviazki grudnogo protoka.

In 80 Wistar rats by means of electroroentgenolymphography lymphatic pathways and thoracic duct have been studied, normal and after ligation of the latter in 1-3 days, 1 and 2-3 months. Contrasting of the thoracic duct in the control animals reveals its additional ducts, that run in parallel to the main collector and they get into it after a certain distance, as well as different time phases of filling the duct are noted. When the thoracic duct is ligated, in 1-3 days dilatation of the ductal cistern, contrasting of lymphatic vessels and nodes in other regions are observed. In 1 month of the experiment the thoracic duct cistern is poorly expressed in comparison with the early time. The contrast substance continues to get into the group of the lymph nodes in other regions. A network of anastomoses of lymphatic vessels is formed in the area of ligation. In 2-3 months, when the contrast substance continues to get retrogradely into other groups and regions of the lymph nodes, final restoration of the lymph-flow takes place at the expense of formation of collateral pathways.

[Possibilities of indirect electroroentgenolymphography of the mediastinum in an experiment]. / Vozmozhnosti nepriamoi élektrorentgenolimfografii sredosteniia v éksperimente.

Using various roentgen contrast preparations and different means of their administration, an optimal contrasting of the mediastinal lymphoapparatus is obtained, when colloid solutions (thorotrast) are injected intraperitoneally. Electroroentgenography with multiple magnification by means of the apparatuses REIS-D and ERGA-02 reveals lymph nodes in the mediastinum of small laboratory animals. Owing to the results of the investigation, it is possible to plan further steps for perfection of the experimental and, later on, clinical lymphography of the mediastinum.