Features of the structure of the mesenteric and tracheobronchial lymph nodes in rat offspring after exposure to tetracycline

Ante- and postnatal development of anatomical structures and cells of lymphatic nodes has been studied in rat offspring subjected to tetracycline effect during placentation and organogenesis (the 8th-14th days) and during fetogenesis (the 15th-20th days). Tetracycline injection during the 8th-14th days of embryogenesis results in certain disturbances of the nodular structure formations, inhibition of lympho- and plasmo-cytopoesis against the background of a sharp increase in number of basophilic granulocytes and tissue basophils. The antibiotic effect on the 15th-20th days of embryogenesis does not disturb the lymph node formation, but produces an increasing number of lymphocytes, plasmocytes, macrophages, eosinophilic granulocytes and tissue basophils in them.     

Mesenteric lymph nodes in the rat after exposure to hydrocortisone

The construction and cell composition of the cortex and medulla have been morphometrically studied after 1-, 3-, 5-, 7- and 14-aliquot injection of medical doses of hydrocortisone (0.25 mg per 100 g of body mass). The body mass of the animals decreases, as does the size of the mesenteric lymph nodes. The lymphocyto- and immunocytopoietic functions intensify in the medullary cords with a simultaneous inhibition of these processes in the cortical plateau and in the lymphoid noduli. On the 5th and 7th days there is some increase in the section area of the cortex, while that of the medulla decreases. The part of small lymphocytes in these structures grows large. Therefore, it is possible to suppose a definite tendency towards restoration of the structural components within two weeks.     

Comparative migration of B- and T-Lymphocytes in the rat spleen and lymph nodes.

B-lymphocytes were obtained either by thoracic duct cannulation of thymectomized, irradiated rats or by isolation of complement-receptor-bearing lymphocytes from normal rats. They were labeled in vitro with [³H]-leucine and injected iv into syngeneic recipients from which samples of spleen and lymph node were taken at intervals from 15 min to 48 hr after injection. The sites of initial localisation of B- and T-lymphocytes were identical suggesting that the cells migrated into both organs by a common entrance. The two cell types remained closely associated for several hours in the paracortex of lymph nodes and at the periphery of the periarteriolar lymphoid sheath of the spleen. After 1–6 hr, B-cells segregated from T-cells by moving on into the adjacent part of the lymphocyte corona in the follicular area. By 24 hr, B-cells were evenly distributed throughout the corona. A definite minority of B-cells but no T-cells were seen within the germinal centres. In the spleen, T-cells moved into the central area of the periarteriolar sheath before returning to the blood. The immunological significance of the routes of B- and T-cell migration is discussed.     

Ontogenetic aspects of immune-complex trapping in the spleen and popliteal lymph nodes of the rat

Summary An ontogenetic approach was used to obtain information about the relation between structure and function of lymphoid tissues. In particular the development of the capacity to trap immune complexes was studied in relation to the development of the lymphoid compartments. For this purpose isologous horseradish (HRP)-anti-HRP complexes were injected into neonatal rats, and their fate was studied in the spleen and popliteal lymph nodes. Immune-complex trapping occurred as soon as primary follicles could be recognized; without follicles no trapping was observed. Several explanations for this simultaneous development of trapping capacity and follicular structure are discussed.Abbreviations i.v. intravenous(ly) - s.c. subcutaneous(ly) - HRP horseradish peroxidase - MZ marginal zone - PALS periarteriolar lymphocyte sheath     

Changes in the lymph nodes of vaccinated rats after prenatal exposure to an antibiotic

Changes of anatomical structures and dynamics of cell composition have been studied in lymph nodes of one-month-old rats, vaccinated with typhoid vaccine and sexta-anatoxin, and of rats vaccinated in a similar way, but their mothers have been given tetracycline at early and late periods of pregnancy. After vaccination in 1, 3 and 7 days lymphocytic, blastic, macrophagal, plasmocytic; mast cells, neutrophilic and eosinophilic reactions have been observed in lymph nodes. In the offspring of the rats, that have been given tetracycline during preimplantation and implantation periods (the 1st-7th days of pregnancy) contents of small, middle lymphocytes, plasmocytes, macrophages, mast cells do not change. Neutrophilic and eosinophilic reactions are revealed only in medullary cords, that demonstrates certain inhibition of the immunological function. In the rats, whose mothers have been given tetracycline during embryogenesis (on the 15th-20th days of pregnancy) vaccination results in a considerable increase of the reactive state of the lymph nodes.     

Structure of the thymus gland, spleen and inguinal lymph nodes of albino rats after immunologic correction during the process of adaptation to physical exercise]

In the experiment performed on 70 noninbred white male rats by means of histological and morphometric techniques construction and cell composition of the thymus, spleen and inguinal lymph nodes have been studied under the influence of systematic physical (swimming) loads. They have been applied under conditions of a pharmacological correction (administration of leacadin) and without it. In the animals not given leacadin, the physical loads result in decrease of the immune function in all the organs investigated. This is evident from decreasing size of the thymus, outgrowth of adipose tissue in it, drop in amount of lymphoid nodules++ in the spleen, decline of contents of lymphocytes in all the organs, and in the cords of the inguinal lymph nodes--decline of plasma cells. Application of leacadin prevents appearance of unfavourable changes.     

Features of the structure of the regional lymph nodes of the duodenum in monkeys

By means of morphometric methods, duodenal regional lymph nodes were studied in rhesus and lapunder macaques. It was demonstrated that in monkeys the connective tissue framework, cortical plateau, medullary substance, cortical substance, sinuses and follicles are expressed differently. Cellular elements in the lymph nodes analysed in the monkeys subjected to a comparative investigation demonstrated their uneven distribution in the same structural components. Small lymphocytes were predominate cellular elements. There were rather essential differences in the number of plasmic cells, mitotically dividing cells, acidophilic granulocytes, mast cells and macrophages. Certain species differences were demonstrated to exist both in structure and cell composition of the lymph nodes that seemed to depend on some local peculiarities of immunogenic reactions.     

Changes in the anatomic structures and cellular composition of lymph nodes after prenatal exposure to oleandomycin

Tracheobronchial and mesenteric lymph nodes have been investigated in 120 embryos, fetuses and newborn (5-, 14-, 30-day-old) rats by means of anatomical, histological and electron microscopical methods. Prenatal influence of oleandomycin phosphate on development of lymph nodes has been analysed. Effect of the drug on the mother--fetus system produces certain reactive changes in the anatomical structures responsible for the barrier-filtration and drainage functions of the lymph nodes. The immunocytopoietic function is inhibited, as demonstrates certain decrease of lymphatic line cells.     

Efferent neural apparatus of the thymus gland, spleen and lymph nodes and its reaction to electric stimulation of the posterior hypothalamic field

At a histochemical investigation of the rabbit lymphoid organs innervation certain peculiarities on histotopography of adrenergic and acetylcholinesterase (AChE)-containing nervous elements have been established. At a chronic experiment by means of a dosed repeated bilateral electrostimulation of the posterior hypothalamic field in the organs mentioned, inhibition of the functional activity has been noticed. It is most specific not for the AChE-containing structures, but for the adrenergic ones, localized to some extent in the parenchyma, as well as along the course of the blood vessels and their adventitium. The results are discussed in terms of modulatory influence of the posterior hypothalamic field on trophic and functions of the lymphoid tissue. This influence is realized both humoraly and via the nervous pathways (either directly using certain ways and connections, or indirectly by means of neurogenic tonus of the intraorganic blood vessels regulation).     

Cytological structure of the lymph nodes after administration of foreign protein]

Changes in the cellular compositon of popliteal lymphatic nodes of albino rats were studied in normality and after injection of a foreign protein. Allergic inflammation was caused by injection of 0,25 ml of the horse serum. Observations were made on the 1, 3, 8, 19 and 30 days after the beginning of experiment. The cellular composition was counted in 30 visual fileds in the cortical plateu, follicles and myelinated cords. The average percentage of cellular elements has been determined. It has been shown that the reticular cells have less changes as compared with other cells in response to antigen stimulation. An inverse correlative relationship was noted between small and medium-sized lymphocytes. The greatest percentage of plasmic cells was noted in myelinated cords; in the follicles they are found as solitary units. In the primary immunization the cellular composition of follicles was little changed as compared with the cellular composition of the cortical and medullary substance. The cellular reaction was most pronounced in myelinated cords. Thus, the investigation of the cellular composition of different structure components of the rat's lymphatic nodes after injection of the foreign protein has revealed a different degree of their reaction.     

Clasmatosis: Ultrastructure of cytoplasmic fragments from the spleen,lymph nodes,and thymus of the rat

Summary The cytoplasmic fragments forming as a result of clasmatosis were isolated by centrifugation from cellular suspensions of the spleen, submandibulur lymph nodes and thymus of August rats and were studied electron microscopically. It has been established that the cytoplasmic fragments widely vary in organelle saturation within the same organ and that this saturation diminishes in the spleen-lymphatic nodes-thymus series. With the exception of the centrioles and the Golgi complex the cytoplasmic fragments may contain any cytoplasmic organelles and inclusions characteristic of lymphoid cells. The results have been discussed from the point of view of the possible relation of clasmatosis to the process of lymphocyte maturation.     

Morpho-functional status of the lymph nodes of rats during rehabilitation after exposure to vapors of dimethyl sulfate]

By means of histological methods inferior tracheobronchial lymph nodes have been investigated in 48 Wistar rats in 2 weeks and 3 months after cessation of inhalation of DNSV at maximum possible dose (0.1 mg/m3) for 2 and 14 days. Cell composition of the lymph nodes and cross sections of structural components have been compared. The cross section of the cortex decreases, while that of the medulla increases in comparison with corresponding parameters of the acute experiment. In 2 weeks and 3 months after DMSV effect for 2 days the part (%) of poorly differentiated cells and middle lymphocytes increases, while content of plasma cells in the medullary cords decreases. During rehabilitation after DMSV effect for 14 days a low level plateau is noted (as in the acute experiment). However, in lymphoid nodules++ within content of the poorly differentiated cells and middle lymphocytes in the cortical germinative centers in 2 weeks and 3 months the number of the poorly differentiated and reticular cells increases essentially, as well as mitotically dividing cells (in comparison to the acute experiment). In the medullary cords of the lymph nodes after 3 months of rehabilitation content of immature plasma cells is essentially higher than in 2 weeks of rehabilitation and than in the acute experiment. During rehabilitation the level of cells destruction in the lymph nodes noticeably decreases in comparison to the acute experiment.     

Thein vitro activity of the microsomal fraction isolated from the spleen and the lymph nodes after immunization of the donor

The microsomal fraction from the spleen (after perfusion) of immunized rabbits incubated for 20 min at 37° C under usual conditions in the presence of energy sources incorporates¹⁴C-labelled amino acids both into the solubilized (by adding deoxycholate), and into the nonsolubilized part (15%). The cell supernatant incorporates under these conditions the¹⁴C-labelled amino acids into total proteins in the absence of microsomes but in a lower degree. The cell supernatant contains gamma globulin detectable by immunoelectrophoresis. Gamma globulin obtained by specific precipitation of the solubilized microsomal fraction with antigamma-globulin serum had an measurable radioactivity. The precipitate of gamma globulin obtained from the supernatant of the incubation medium in the same manner (after removing the microsomes) had a specific activity twice as high. On separating the microsomal fraction extract and the incubation medium supernatant on DEAE cellulose most fractions show on extinction maximum at 260 nm in the first case and at 280 nm in the second case. The microsomal fraction isolated from the spleen and lymph nodes of immunized pigs-48 and 72 h after revaccination, when incubatedin vitro, incorporated¹⁴C-labelled amino acids into total protein. After ultrasonic disintegration in 0.14m NaCl and filtration through a Sephadex G 25 column it is specifically precipitated with the antigammaglobulin serum. Gamma globulin isolated after incubation of the microsomal fraction had a measurable radioactivity. AntiHSA antibodies determined by adsorption on immunosorbent did not possess significant radioactivity. Only the concentrated supernatant of the incubation medium showed minute radioactivity of 75–94 counts/min /ml. The problem of investigating the formation of nascent specific antibodies on a subcellular levelin vitro during the early period of secondary response to the antigen is discussed, in particular the problem of their detection. An erratum to this article is available at .     

The reaction of somatic lymph nodes to experimental exposure to sulfide baths]

Influence of strong sulfide baths of the sanatorium "Talgi" to the popliteal and superficial inguinal lymph nodes (LN) has been studied in 35 rats (140-150 g of body mass) and 15 animals have been used as the control. The slices are stained with hematoxyli-eosin, after van Gieson, Romanovsky-Giemsa, Kurnik and silver nitrate impregnation after Foot. The section area of the LN decreases, but amount of lymphoid nodules increases (especially in deep layers of the cortex). In the germinative centers amount of middle lymphocytes and mitoses becomes larger. In the internodular zones of the popliteal nodes amount of macrophages and eosinophiles enlarges significantly, and in the inguinal-amount of mast cells and eosinophiles. In the medullary sinuses amount of macrophages declines. In the medullary cords amount of immature plasma cells and blasts increases, while amount of mature cells decreases.     

Lymphocyte subset analyses in blood, spleen and lymph nodes of female Sprague-Dawley rats after short or prolonged exposure to a 50 Hz 100-microT magnetic field.

Based primarily on the results of in vitro studies, it has been suggested that power-line (50 or 60 Hz) magnetic fields (MFs) may reduce immune function, which could lower resistance to infection or cancer. This study was conducted to evaluate the influence of acute and chronic in vivo exposure to a linearly polarized 50 Hz MF on immune function in female Sprague-Dawley rats. Groups of rats were exposed continuously to the MF at a flux density of 100 microT for periods of 3 days, 14 days or 13 weeks. For each exposure period, one control group of rats was sham-exposed together with each MF-exposed group. Experimental end points included analyses of T-lymphocyte subsets as well as other immune cells involved in cell-mediated immune responses, i.e. natural killer (NK) cells, B lymphocytes, macrophages, and granulocytes in blood, spleen and mesenteric lymph nodes. In addition, immunohistochemical methods were used to detect proliferating and apoptotic cells in the various compartments of spleen tissue. The results obtained failed to demonstrate a significant effect of short or prolonged MF exposure on different types of leukocytes, including lymphocyte subsets. Furthermore, the experiments on the in vivo proliferation activity of lymphocytes and the extent of apoptosis in spleen samples did not indicate a difference between the MF-exposed and sham-exposed groups, indicating that MF exposure does not affect the mechanisms involved in the control of lymphocyte homeostasis. The lack of MF effects in the immune tests used in the present in vivo study makes it highly unlikely that MF exposure induces immunotoxicity, at least under the experimental conditions used. However, the data do not exclude the possibility that functional alterations in T-cell responses to mitogens and in NK cell activity as recently described for MF-exposed rodents may be one mechanism involved in the carcinogenic effects of MF exposure observed in some models of co-carcinogenesis.