Transferase contents in lymph and blood in fever reaction]

The aim of the present investigation was the study of the content of alanine, asparagine-transaminases, gamma-glutamyl transferase and their isoenzymes, as well as leucine aminotransferase in the lymph of thoracic duct, hepatic and intestinal lymph and peripheral blood in dynamics of fever reaction of various duration in the experiments on rabbits. Irrespective of its duration, the fever was followed by a significant activation of the enzymes in the body fluids. However, in many-day fever reaction, a rise of enzymes level in the lymph was more prolonged than that in the blood. The above studies make it possible to assume that the released enzymes in fever reaction are primarily resorbed by lymphatic capillaries and their activity indices in the blood serum are largely evidenced by the transport function of the lymphatic system.     

Activity of several carbohydrate exchange enzymes in the lymph during fever reaction

This work includes a comparative study of aldolase enzyme activity, LDG and its isoenzymes in thoracic duct lymph and blood serum of rabbits in fever reaction dynamics of various duration. Irrespective of its duration the fever was followed by a significant activation of investigated enzymes in the body liquids. However, in many day fever reaction a rise of LDG level in the lymph was more prolonged then that in the blood. The above studies make it possible to assume that the released enzymes in fever reaction are primarily resorbed by lymphatic capillaries and their activity indices in the blood serum are largely evidenced by the transport function of the lymphatic system.     

Morpho-functional changes in the lymph nodes during fever reaction]

Lymph nodes (mesenteric, popliteal, cervical) of rabbits in fever reaction of different duration have been studied in our work. As a whole morpho-functional changes in lymph nodes in fever reaction indicate the increase of their functional activity: hyperplasia of lymphatic substance with the growth of lymphocytes number and slightly differentiated lymphoid cells in follicles and paracortical zone, hyperplasia of pulposus bands, the signs of macrophagal reaction and plasmatization of lymph nodes are to be observed and all these create prerequisites for the increase of tensity of cellular and humoral immunity. Simultaneously the signs of destruction of cellular elements--lymphocytolysis in the porta tract and the growth of number of PAS-positive cells in the parenchyma of the nodes take place.     

Species and organ dependence of alkaline phosphatase activity in lymphatic tissues. A histochemical, biochemical and electrophoretic study

Synopsis Alkaline phosphatase activity in lymphatic tissues of guineapig, cat, cow, dog, rabbit, sheep, rat, mouse, hamster, chicken and man was studied with histochemical, biochemical and electrophoretic techniques. The thymus showed decreasing alkaline phosphatase activity from species to species in the order just given. Activity of alkaline phosphatase in other lymphatic tissues did not show such clear species and organ dependence. Spleens of the cat, cow and rabbit and lymph nodes of the cow and sheep gave, however, very characteristic patterns of alkaline phosphatase activity. In the chicken there was no difference between the alkaline phosphatase content of the thymus and that of the bursa of Fabricius. The lymphatic follicles of human tonsils and appendix and in the appendix of the rabbit exhibited alkaline phosphatase activity in the circular cell layer. This was also seen in some follicles in the lymph nodes of certain species. Electrophoretically, the main alkaline phosphatase fraction of the lymphatic tissues closely resembled the main fraction of blood, though it is probably not identical with it. Although the biological function of alkaline phosphatase is unknown, the greatly varying alkaline phosphatase content in different lymphatic organs of different species indicates that immunological studies with one species or with cells derived from a certain lymphatic tissue or with both are probably not directly comparable with studies using other species or cells from other lymphatic tissues.     

Role of the lymphatic system in the transport of biologically active substances in shock of various etiologies

The content of histamine, serotonin, adrenaline and noradrenaline in the thoracic and lymphatic duct lymph and blood as well as absolute quantity of lymph transported biogenic amines and mediators into the general circulation were studied on 68 dogs during anaphylactic and endotoxin shock (ASh and ESh, respectively). Both ASh and ESh were accompanied by considerable changes in the hemodynamics, lymph circulation, content of biologically active substances in lymph and blood and in their lymph transport to the blood stream. The most profound and early changes in the content of biologically active substances during ASh and ESh were found in the lymph, which shows an important role of the lymphatic system in their resorption and transport from organs and tissues into the general circulation.     

Aging‐related anatomical and biochemical changes in lymphatic collectors impair lymph transport,fluid homeostasis,and pathogen clearance

The role of lymphatic vessels is to transport fluid, soluble molecules, and immune cells to the draining lymph nodes. Here, we analyze how the aging process affects the functionality of the lymphatic collectors and the dynamics of lymph flow. Ultrastructural, biochemical, and proteomic analysis indicates a loss of matrix proteins, and smooth muscle cells in aged collectors resulting in a decrease in contraction frequency, systolic lymph flow velocity, and pumping activity, as measured in vivo in lymphatic collectors. Functionally, this impairment also translated into a reduced ability for in vivo bacterial transport as determined by time‐lapse microscopy. Ultrastructural and proteomic analysis also indicates a decrease in the thickness of the endothelial cell glycocalyx and loss of gap junction proteins in aged lymph collectors. Redox proteomic analysis mapped an aging‐related increase in the glycation and carboxylation of lymphatic's endothelial cell and matrix proteins. Functionally, these modifications translate into apparent hyperpermeability of the lymphatics with pathogen escaping from the collectors into the surrounding tissue and a decreased ability to control tissue fluid homeostasis. Altogether, our data provide a mechanistic analysis of how the anatomical and biochemical changes, occurring in aged lymphatic vessels, compromise lymph flow, tissue fluid homeostasis, and pathogen transport.     

Endothelial cell barriers: Transport of molecules between blood and tissues

An endothelial cell monolayer separates interstitia from blood and lymph, and determines the bidirectional transfer of solutes and macromolecules across these biological spaces. We review advances in transport modalities across these endothelial barriers. Glucose is a major fuel for the brain and peripheral tissues, and insulin acts on both central and peripheral tissues to promote whole‐body metabolic signalling and anabolic activity. Blood‐brain barrier endothelial cells display stringent tight junctions and lack pinocytic activity. Delivery of blood glucose and insulin to the brain occurs through their respective carrier (Glucose transporter 1) and receptor (insulin receptor), enacting bona fide transcytosis. At supraphysiological concentrations, insulin is also likely transferred by fluid phase cellular uptake and paracellular transport, especially in peripheral microvascular endothelia. The lymphatic microvasculature also transports insulin but in this case from tissues to lymph and therefrom to blood. This serves to end the hormone's action and to absorb highly concentrated subcutaneously injected insulin in diabetic individuals. The former function may involve receptor‐mediated transcytosis into lymphatic endothelial cells, the latter fluid phase uptake and paracellular transport. Lymphatic capillaries also mediate carrier‐dependent transport of other nutrients and macromolecules. These findings challenge the notion that lymphatic capillaries only transport macromolecules through intercellular flaps.     

Enzyme activities in thoracic duct lymph and plasma of anaesthetized, conscious resting and exercising dogs

The significance of changes in lymph flow for the extracellular distribution and transport of cellular enzymes and for the level of enzyme activities in plasma was investigated. Specimens of thoracic duct lymph were obtained from an extracorporal lymph shunt in anaesthetized, conscious resting and treadmill exercising dogs (6 km X h-1 for 1 h) The activity of 10 enzymes and of protein content in lymph and plasma were studied, as well as lymph flow, lymphatic transport, and the lymph-plasma ratio of these compounds. Lactate, pH, and blood gases were monitored in venous blood. Lymph flow of 0.80 ml X min-1 in anaesthetized dogs more than doubled (to 1.86 ml X min-1) when the animals were conscious and resting. In anaesthetized dogs lymph enzyme activity was higher only for enzymes of predominately hepatic origin, such as choline esterase (CHE) and alanine aminoferase (ALAT), and was lower for aspartate aminotransferase (ASAT) and aldolase (ALD). In conscious dogs, due to activation of the skeletal muscle "tissue pump", lymphatic transport of enzymes with rather high activity in skeletal muscle, and of protein, is significantly enhanced. Enzyme activities in plasma, however, did not differ between the groups. Lymph-plasma activity ratios higher than one were found for lactate dehydrogenase (LDH), malate dehydrogenase (MDH), ASAT, creatine kinase (CK), ALD, and phosphohexose isomerase (PHI). Exercise stimulated lymph flow up to 4.9 ml X min-1, and increased the lymphatic activities of those enzymes with a lymph-plasma ratio higher than unity, these enzymes increasing in the plasma due to the highly increased lymphatic transport.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cytological composition of lymph in fever reaction

This work deals with an investigation into the lymph cytologic composition of thoracic lymph duct of rabbits in fever reaction (FR) of various duration. FR was accompanied by quantitative and qualitative shifts in lymph cytologic composition. There was an alternative rise and fall of the leucocyte number in the first hours of fever. The number of little and medium leucocytes decreased while the number of eosinophiles, insufficiently differentiated cells-blasts, large lymphocytes, prolymphocytes increased. Our investigations revealed a significant role played by the lymphatic system in lymphoid cells mobilization in FR, which is evident by a considerable lymphocyte number gaining entrance to the blood through thoracic duct.     

Enzyme activities as electron microscopic markers of bile and bile thrombi in the study of cholestasis

Summary An electron microscopical study of several phosphatases in liver tissue was made in different forms of cholestasis. The material included a biopsy from a case of giant cell hepatitis, dog liver after experimental common bile duct ligation, and rat liver under the same experimental conditions. A positive reaction of several phosphatases was noted in the sites of intra and extracellular accumulation of bile constituents. It is suggested that the activity of phosphatases, especially the alkaline phosphatase activity, can be useful as an electron microscopic marker of intracytoplasmic and intercellular bile constituents in the study of bile transport and bile regurgitation. The supposition is made that the intracytoplasmic bilirubin carrier protein can be of enzymatic character.     

Effect of the fever reaction on the kallikrein-kinin system of the lymph and blood

The dynamics of kallikrein-kinin system components in the lymph of thoracic duct and blood following fever reaction of various duration has been studied in the experiment on rabbits. The experiments have shown that in prolonged fever reaction there are qualitative disorders in kinin system components ratio indicative of break in the system of regulatory links, its exhaustion and transformation of the physiological reactions into the pathogenic ones. One may assume that changes in kallikrein-kinin system activity in body fluid are the links in the complex of pathogenic disorders in the organ and system functional activity during prolonged fever reaction.     

Lymphatic transport of cellular enzymes from muscle into the intravascular compartment.

In an experimental study, employing anaesthetized dogs, it was investigated whether cellular enzymes from peripheral skeletal muscle get into the circulating blood by diffusion across capillary membranes or by lymphatic transport. In the experimental group 1, the animals were anaesthetized only. The plasma activities of the four enzymes measured--lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, creatine kinase--did not show any mentionable change during a time period of 6 h. In group 2 one hind limb of each animal was moved passively for 1 h. Alanine aminotransferase remained unchanged in plasma, the activities of the three other enzymes increased significantly. In group 3 one hind limb was made hypoxic by clamping the femoral blood vessels for 1 h. No activity changes were observed. When the period of hypoxia was followed by a 1-hour period of passive movement in group 4, the alterations in plasma activities were almost identical to those observed in group 2. In group 5 the experimental procedure was as in group 4, in addition the lymph from the thoracic duct was quantitatively withdrawn. The enzyme activities in plasma revealed a tendency to decrease rather than increase. Lymph flow increased significantly as well as the lymphatic activities of those enzymes which have high intracellular activities in muscle. The results prove, that enzymes from muscle are transported from the interstitial into the intravascular compartment mainly by lymphatic transport. Indications were found that the interruption of blood flow in one hind limb did not result in an enzyme release from muscle cells. It is discussed how changes in lymph flow, occurring during physical exercise for example, affect enzyme activities in plasma.     

Evaluating flux of labeled albumin into the pulmonary interstitium of sheep lungs.

A noninvasive method was used to measure the movement of 131I-labeled albumin across the pulmonary microvascular barrier of a blood-perfused in situ sheep lung lymph preparation. After injection of labeled albumin into the blood, external measurements of gamma activity were taken for 2 h. The interstitial concentrations were calculated by applying the external activities and sampled lung lymph concentrations to a mass transport model. For the external activities and lymph activities to yield the same quantitative results, two modifications were necessary. First, lymph concentrations were corrected for transport delay from the lymphatic system. Second, externally detected radioactivity had to be corrected for the contribution of unbound nuclide. Application of a mathematical model to the data indicated the extravascular distribution volume for albumin was 79% of the pulmonary blood volume, and the extravascular distribution volume for radiolabeled iodide was 4.42 times greater than the pulmonary blood volume. The permeability-surface area product for iodide in the lung was estimated to be 0.274 ml.min-1.g blood-free dry lung wt-1. The transport delay in the lymphatic system was approximately 30-45 min and represented a volume of 1.44-2.80 ml.     

Enzyme-histochemical identification of lymphatic vessels by light and backscattered image scanning electron microscopy

The walls of lymphatics are characterized by strong 5'-nucleotidase activity, whereas those of blood capillaries reveal significantly lower or no activity. Alkaline phosphatase activity, on the other hand, is markedly higher in blood capillaries than in lymphatic vessels. On the basis of such characteristics, lymphatics and blood capillaries were distinguished histochemically in rat stomach using 5'-nucleotidase-alkaline phosphatase double staining. The distribution and intensity of lead-demonstrated 5'-nucleotidase activity in lymphatic vessels could be determined by comparing the images of the same histochemically stained cryostat section as seen by light and backscattered image scanning electron microscopy. The specificity of the 5'-nucleotidase reaction was obtained by inhibiting nonspecific alkaline phosphatase by including L-tetramisole in the 5'-nucleotidase incubation medium. The products of the 5'-nucleotidase activity were deposited on the outer surface of the plasma membrane of the lymphatic endothelial cells.     

Enzyme-Histochemical Identification of Lymphatic Vessels by Light and Backscattered Image Scanning Electron Microscopy

The walls of lymphatics are characterized by strong 5'-nucleotidase activity, whereas those of blood capillaries reveal significantly lower or no activity. Alkaline phosphatase activity, on the other hand, is markedly higher in blood capillaries than in lymphatic vessels. On the basis of such characteristics, lymphatics and blood capillaries were distinguished histochemically in rat stomach using 5'-nucleotidase-alkaline phosphatase double staining. The distribution and intensity of lead-demonstrated 5'-nucleotidase activity in lymphatic vessels could be determined by comparing the images of the same histochemically stained cryostat section as seen by light and backscattered image scanning electron microscopy. The specificity of the 5'-nucleotidase reaction was obtained by inhibiting nonspecific alkaline phosphatase by including L-tetramisole in the 5'-nucleotidase incubation medium. The products of the 5'-nucleotidase activity were deposited on the outer surface of the plasma membrane of the lymphatic endothelial cells.     

Lymphatic smooth muscle: the motor unit of lymph drainage

Embedded into the wall of collecting lymphatic vessels and trunks, the lymphatic smooth muscles are cardinal to the functions of the lymphatic system. Their intrinsic contractile property--the intrinsic lymph pump--through rhythmical and phasic contractions of the vessels, represents the principal mechanism by which lymph flow is generated. Through changes in tonic constrictions, lymphatic smooth muscles also modulate lymph flow resistance. Lymphatic smooth muscles are sensitive to physical and chemical stimuli, mediating changes in their activity and modulating lymphatic drainage. Because lymphatic smooth muscles play such an important role in fluid transport, their dysfunction may be a component of many inflammatory disease states. This review presents recent findings on the physiology and cellular biology of lymphatic smooth muscles and discusses the importance of these cells for the function of the lymphatic system in physiological and pathophysiological situations.     

Intestinal alkaline phosphatase release is not associated with chylomicron formation

Intestinal alkaline phosphatase (IAP) is one of the major sources of alkaline phosphatase in circulation. It is secreted into the intestinal lumen, serum, and lymph. After the ingestion of lipid, lymphatic alkaline phosphatase secretion increases significantly. We have found that the nonabsorbable fat olestra is unable to stimulate lymphatic alkaline phosphatase secretion. We also found that the hydrophobic surfactant Pluronic L-81, which blocks chylomicron formation, fails to inhibit this increase in lymphatic alkaline phosphatase secretion. These results suggest that it is the lipid uptake into the mucosa and/or reesterification to form triacylglycerols, but not the formation of chylomicrons, that is necessary for the stimulation of the secretion of alkaline phosphatase into the lymph.     

Contractile activity of lymphatic microvessels in fever reaction

Contractile activity of the wall and lymphatic microvessels (LM) valves of small intestine mesenterium in experimental fever reaction (FR) under vital microscopy conditions has been studied in the experiments on rats. FR was accompanied by considerable quantitative (the increase of the number of contractile LM and their valves, the rising of their contractile activity) and qualitative changes of LM contractile activity. The increase of spontaneous vasomotions frequency and closing of valves cusps was observed. Contractile apparatus of the wall and LM valves becomes more active in FR due to biogenic amines mobilization from perivascular sympathetic terminals and mast cells.     

Transdiaphragmatic lymphatic transport of intraperitoneally administered marker in hamsters.

OBJECTIVE: To determine whether transdiaphragmatic transport in hamsters is similar to that described in other animals by examining transport of an intraperitoneally administered marker. METHODS: Monastral blue B suspension was administered intraperitoneally to 28 male Syrian hamsters (Mesocricetus auratus). Four hamsters each were euthanized 7, 15, and 30 min, and 1, 2, 3, and 24 h later. Specimens were examined microscopically for presence of marker. RESULTS: Marker was present in intrathoracic lymphatic vessels and cranial and caudal mediastinal lymph nodes by 7 min after its administration. The amount of marker in lymph nodes increased with time. The subcapsular distribution of marker was consistent with lymphatic transport. By 1 h after its administration, marker was present in the liver, spleen, bone marrow, and mesenteric and mandibular lymph nodes. Patterns of marker distribution in these tissues were consistent with hematogenous transport, but the amount of marker was considerably less than that in the intrathoracic lymph nodes at corresponding times. CONCLUSIONS: Particulates were most likely translocated from the hamster peritoneal cavity to intrathoracic lymph nodes via transdiaphragmatic lymphatic vessels. A portion of the translocated particulates entered the blood, where they were distributed to a variety of tissues within a short time.