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In pregnant Wistar rats an essential rearrangement of the uterine blood-lymph circulatory bed has been revealed. It is possible that at the beginning of pregnancy it occurs for the change of the histiotrophic nutrition of the embryo into the hemotrophic one under effect of the trophoblast. Later on, when hemochorial relations between the mother and the fetus have been established, the continuous growth of the volumetric density and diameter of the vessels of the uterine microcirculatory bed can be connected with the intensive growth of the fetus and the extension of the yolk and allantois circulation reservoir. During these periods of pregnancy the mass of the placental labyrinth is doubled and vascularization of the extraembryonic organs increases. The circulatory changes occurring in the uterine placental zone get their reflection in the uterine regional lymph nodes. The investigation of the ultrastructural organization of endotheliocytes in the blood capillaries of the rat iliac lymph nodes during pregnancy reveals a complex of adaptive-structural rearrangements in them, first of all enlargement of the lumen in the arterial and venous parts of the capillaries, increasing fenestration of the arterial and venous parts of the capillaries, enhancing formation of micropinocytic vesicles and transendothelial canals. Thus, the complex of adaptive-compensatory rearrangements and interconnected, integrated reaction of the uterine microcirculatory bed with the analogous system of its regional iliac lymph nodes is revealed.

The experiments on rats have shown that coronary artery ligation reduces the content of microsomal cytochromes P-450 and b5 and causes amidopyrine-N-demethylation and aniline-p-hydroxylation disturbances that persist throughout a 3-week period of myocardial infarction. The investigation of spontaneous lipid peroxidation of microsomal membranes in myocardial infarction has shown that concentration of malonic dialdehyde in microsomal fraction significantly increased by the 7th day after coronary artery ligation, as compared to sham-operated rats.

At total overheating a manifested macrophagal reaction is observed in the rat somatic lymph nodes. Concentration of autoantigens in tissues increases, that results in transformation of small lymphocytes towards lymphoblasts and plasma cells. When manifested disorders of hemo- and lymphocirculation are present, eosinophils and mast cells, being tissue regulators of microcirculation and wall permeability of blood capillaries and lymphatic sinuses++., increase in number.

Administration of benzpirene to the mother is accompanied with activation of B-and decrease in T-links of immune activity both in the mother and offspring. The lymphoid organs in the animals, not subjected antenatally to benziprene action, but given the substance after birth, undergo destabilization and are not ready to administration of this polycyclic hydrocarbonic compound. This produces their hypoplasia. It is quite possible, that under this condition the activity of the cellular link of immunity decreases, and the humoral one is stimulated. Certain morphofunctional connections are supposed to exist between the immune systems of the mother and the fetus. The antenatal action of benzpirene causes a responsive reaction in the offspring as an immunological commemoration, and it ensures the level of the immune response.

From the body of the rat uterus, the lymph outflows into the caudal lymph nodes and when the latter are absent--into the iliac lymph nodes. From the medial and middle parts of the uterine horn the lymph out flows into the iliac lymph nodes, and from the lateral part of the uterine horn--into the renal lymph nodes. Some parts of the lymph outflows into corresponding contralateral lymph nodes. If the mass of the caudal lymph nodes in pregnant animals does not significantly differ from those in nonpregnant animals, the mass of the iliac and renal nodes increases with pregnancy. Maximal increase of the iliac and renal lymph nodes mass coincides with completion of the alantoic placenta formation. It is probable that there is a positive correlative dependence between the number of embryos in the uterus and the mass both of the iliac and renal lymph nodes.

An original rapidly acting tensoresistive pressure transducer was used to study the lymph pressure in the popliteal and mesenteric lymph nodes and vessels of the dog without liquid injection into the lymph channels. The characteristics of the lymph flow in the drained organs was compared at a relative rest, while for the mesenteric lymph channels at the height of digestion. During digestion the lymph pressure in the vessels and nodes is 2-3 times higher than on an empty stomach, and the waves of tonic activity occur more frequently and energetically. The lymph pressure in the lymph nodes is lower than in the efferent vessels of these nodes.

The amount of plasma cells is connected with intensity of humoral immunological reactions. In people died an accidental death, the amount of immature plasma cells is the least in the axillary and the greatest--in the mesenteric nodes, especially in the thymus-independent zone. The amount of lymphoblasts and large lymphocytes, reflecting intensity of the humoral and cellular immune reactions, is also the greatest in the mesenteric lymph nodes, both in the thymus-dependent and in the thymus-independent zone. In all probability, the intensity of the immunological processes is minimal in the axillary, it is middle in the iliac and cervical and it is maximal in the mesenteric lymph nodes. In each case it is probably connected with peculiarities of antigenic composition of the lymph inflow. The mesenteric lymph nodes are on the way of the foreign protein getting into the intestine. This is evidently reflected by the highest content of immature plasma cells, lymphoblasts and large lymphocytes in them.

In the regional lymph nodes of the uterus the comparative volume of the paracortical zone significantly increases, especially within the period of the 13th-17th days of pregnancy. In the popliteal lymph node similar effect is not discovered. From the 7th up to the 11th day edema, vasodilatation, infiltration with special leucocytes are revealed. Endothelium of the postcapillary venules is hypertrophied, contains many migrating lymphocytes, which accumulate around the vessels mentioned. The volume of the microcirculatory bed is moderately increased. By the 17th day plasmoblasts, plasmocytes, Motta's cells, monocytes and especially macrophages appear in the paracortical zone. In B-zones and in medullary sinuses blasts, plasma cells, monocytes, macrophages, mitotically deviding cells increase in number. The part of the reticular cells decreases. The tensometric method demonstrates an increasing pressure of lymph in the iliac lymph node at pregnancy. Collateralies appear in the ovarian vein system, in the broad ligament of the uterus, in the lumbar area. The uterine vascular system is supposed to participate in adaptation to pregnancy. In genesis of the regional lymph node changes, discirculatory shifts, predominating during placental organogenesis, combine with phenomena of cell migration and proliferation (clearly revealed by the time when formation of the placenta is completed).

The structure of the postcapillary venules in the rat lymph nodes has been studied after a single total overheating at 43.5 degrees C. During the first three days an essential role is played by ultrastructural destructive processes, that demonstrate certain unfavourable states in cells. Nevertheless, the postcapillary venules perform their function quite satisfactory and even increase small lymphocytes transfer. The 7th-15th days are characterized with a steady compensation of the functional activity of these microvessels. By the 30th day some unfavourable changes in the endothelial ultrastructure are noted. This is, evidently, connected with a steady effect of the plasma toxic factor on the endothelium.

Using light and electron microscopy and morphometry, the morphological changes in the lymph nodes of arterial and venous parts of capillaries were studied on the 11th, 17th and 21st days of pregnancy in rats. Ultrastructural changes in endothelial cells of blood vessels in the uterine lymph nodes during normal pregnancy are of adaptive nature and are possibly responsible for the relief of the blood congestion in the system of the inferior vena cava and for the improvement of the utero-placental circulation.

Modern pharmacological agents used in experimental and practical medicine to stimulate the drainage function of the lymphatic system are discussed. Lymphotropic agents differ by the chemical structure and mechanism of action. Much attention is paid to the analysis of the agents possessing the osmotic effect. Particular emphasis is given to natural bioflavonoids including new polyphenol compounds produced from the Siberian plants.

Structural adaptation of the vascular bed in the broad ligament of the dog uterus has been studied at various time of the experimental phlebohypertension. Restitution of the circulation after the posterior vena cava occulsion occurs phasically. The venous collateralies are not formed at one time and it is connected with the venous pressure level in the inferiocaval system and with some changes in the construction of the microcirculatory bed. Basing on the morphometry data, a general equation has been derived which reflects dynamics of the microangiological parameters and demonstrates unidirectionness of the adaptive reactions in the vascular bed at the disturbed venous circulation. Using principles of the system-structural analysis and the mathematical graph theory, we consider the microcirculatory system of the broad ligament of the uterus as a graph-system and study the reorganization of the microcirculatory network at a venous congestion. Realization of the compensatory possibilities is reached in the microcirculatory bed by a changed relationships in the number of the intervascular connections. The latter are estimated according to the graph-schemes of the microvascular bed. Morphokinetics of the connections between the vessels is characterized by widening or narrowing the borders of the "adaptive norm" and by changing the microangioarchitectonics. At the same time, there is noted formation of specialized microhemoangioconstructions. Morphofunctional state of the lymphatic system is connected with reorganization of the angioarchitectonics. This is certain manifestation of the law of the lymphatic and blood beds "synergism". Thus, the structural changes of the vascular bed are aimed to support a certain hemodynamic level.

Structural and functional changes in the dog liver and regional lymph nodes lysosomes were studied during toxic hepatitis induced by CCl4 administration (single and repeated). Total activity of lysosomal enzymes (acid RNA-ase and beta-galactosidase) was higher in the regional lymph nodes than in the liver, reflecting the barrier, protective function of the organ. During acute toxic hepatitis the specific activities of acid RNA-ase and cathepsin D displayed a sharp rise. No normalization of the indices under study occurred during the observation period (from 8 to 30 days). At the same time there was a rise of the regional lymph node weight and an elevation of the relative macrophage and neutrophil content in the sinuses. The increased activity of the lysosome enzymes in the regional lymph nodes in injury of the liver was connected with greater functional load on the lymph nodes effecting hydrolysis of biopolymeres which penetrated into the regional lymphatic node with the lymph.

A study was made of the content of corticosterone, thyroxine and triiodothyronine in the blood, of the thymic weight and cytomorphological characteristics of rat lymph nodes during prolonged cold (4-5 degrees C) adaptation. Interrelated alterations in the characteristics under study were revealed at different stages of adaptation. The morphofunctional recovery of the lymphoid tissue occurs in the phase of the increased specific stability in spite of the fact that the action of cold is continued and the blood corticosterone concentration is elevated. A new type of the endocrine-lymphoid relationships is supposed to be formed during lengthy adaptation, with this type being different from that both in the starting state and acute stress.

Experiments, performed on CBA mice demonstrate that all the parameters of lymph nodes of various localization possess a diurnal rhythmicity. Certain lympho-endocrine connections participate in realization of the regional peculiarities of the diurnal rhythms via regulation of redistribution of streams of the migrating lymphoid cells, that form the lymph node structures. There are certain differences in endogenous glucocorticoids action, depending on the level of the motor activity, that determines level of the mast cells activation, value of lymph-formation and blood stream intensity in the drained region. Concrete examples of the diurnal spatial-time organization of functional steps are described in inguinal, mesenteric and bifurcational lymph nodes.