Collecting Lymph Vessels Research Articles

Demonstration of the intralobular lymphatics in the guinea pig pancreas by an enzyme-histochemical method.

Intralobular lymphatics in the guinea pig pancreas were demonstrated enzyme-histochemically showing the extent, distribution and fine structure by combined light and transmission electron microscopy. 5'-nucleotidase(5'-Nase)-positive lymphatic vessels were present throughout the pancreas. Intralobular lymphatics among the acini were comparatively rare and generally independent of the blood capillaries, pancreatic ducts and acini. These lymphatics revealed the usual structural features, such as typical intercellular junctions and very tenuous vascular walls without continuous basal laminae. Fine precipitates of the cerium-based reaction product for 5'-Nase activity were found to be associated with cell membranes of the lymphatic endothelium and pinocytotic vesicles. Lymphatics were not closely related to the endocrine islets, although alkaline phosphatase(ALPase)-positive blood capillaries were well developed. Collecting lymphatic vessels with valves with weaker 5'-Nase activity were also detected in the interlobular connective tissue. ALPase activity, absent in the lymphatics, was positive in the blood capillaries, suggesting that it is also a useful way demonstrating, histochemically, the blood capillaries in the guinea pig pancreas.

Effects of bradykinin on lymphatic pumping in rat mesentery.

The effects of bradykinin on lymphatic pump activity of rat mesenteric collecting duct were studied, and the receptor subtype responsible for the bradykinin response was evaluated. Rats were anesthetized with intraperitoneal alpha-chloralose and urethan, and exteriorized mesenteries were studied using intravital microscopic techniques. The diameter of the collecting lymph vessels (approximately 100 microns) was continuously monitored and lymphatic pump parameters (end diastolic diameter, end systolic diameter, stroke volume index, ejection fraction, contraction frequency, and pump flow index) were calculated. Bradykinin (0.1-1.0 nM) did not affect end diastolic diameter, end systolic diameter, stroke volume index, and ejection fraction. Bradykinin increased lymphatic contraction frequency and pump flow index in a dose-dependent manner. Des-Arg9-[Leu8]bradykinin (B1 antagonist, 0.1 microM) had no effect on baseline lymphatic pumping but completely inhibited the bradykinin-induced increase in contraction frequency. N-acetyl-D-Arg-[Hyp3,Thi5,8,D-Phe7] bradykinin (B2 antagonist, 0.1 microM) significantly depressed lymphatic contraction frequency in baseline conditions but had no effect on bradykinin-induced increases in contraction frequency. These results indicate that bradykinin induces positive chronotropic but not inotropic effects on lymphatic pump activity through the stimulation of B1 receptors.

General Anatomy of the Lymphatic System

Lymphatic drainage from an anatomic site tends to be quite anatomically specific. Variation in drainage patterns may be related to individual variation in anatomy or to alteration of drainage pathways by processes such as disease, injury, or surgical treatment. Tumor cells or small groups of tumor cells enter the lymphatic system though the lymphatic saccules and then travel by embolization through the afferent lymphatics. Tumor cells in the afferent lymphatics may travel to a regional node and lodge in the node, or they may bypass the node via alternative channels. Coming from the lymph nodes are efferent lymphatics, which coalesce into collecting ducts that eventually drain into the large veins at the base of the neck, but there are many alternative smaller venous communications.

Topographical anatomy of the bronchomediastinal lymph vessels: Their relationships and formation of the collecting trunks.

This article aims to clarify the topographical relationships of the bronchomediastinal collecting lymph vessels to other structures, in particular the great vessels, the trachea, the esophagus and the mediastinal pleura. Minute dissection was performed on eight cadavers with special reference to the converging collecting lymph vessels which form the bronchomediastinal trunks. On the right side, the trunks were consistently observed on both the right brachiocephalic vein and the subserous surface of the mediastinal pleura (anterior and posterior mediastinal trunks). The pathway from the right recurrent chain nodes ran laterally behind the carotid sheath and led either into the deep cervical nodes situated on the scalenus anterior or directly into the right venous angle. On the left side, the trunks showed varying courses. The nodes from which the trunks arose were constant, and classifiable into three groups: the uppermost paratracheal nodes near the recurrent chain nodes, the anterior mediastinal nodes (the left phrenic nodes) surrounding the phrenic nerve in front of and inferior to the aortic arch (the origin of the superior mediastinal trunk), and the left tracheobronchial nodes (the origin of the inferior mediastinal trunk). The large transverse superficial communicating vessel between the right and left sides was usually found in front of the trachea above the aortic arch; it was often connected to the nodes of the brachiocephalic angle. Deep communications were also found in front of the carina and behind the trachea. These findings allow the collecting vessels from the thoracic viscera to be divided into two pathways on each side: the anterior and posterior mediastinal trunks on the right side, and the superior and inferior mediastinal trunks on the left side. In addition to the four trunks, the superficial communicating vessel between the right and left sides is also drained from the superior mediastinum. The internal mammary lymph chain, which often emptied directly into the venous angle or into the deep cervical nodes, occasionally joined with the right anterior mediastinal trunk or the left superior mediastinal trunk.

The morphology of canine lymphatic valves.

The architecture of 60 valves from thoracic ducts and from renal hilar and mesenteric collecting lymph vessels of dogs were studied by scanning electron microscopy as well as by light and transmission electron microscopy. All of the valves seen in hilar and mesenteric lymph vessels and most of those studied in the thoracic duct were bicuspid. An occasional tricuspid and one monocuspid valve was seen in the thoracic duct. The semilunar cusps of the valves extended from the vessel wall, to which they were attached, towards the valve outlet where adjacent cusps fused. Coincident to the area of fusion was the formation of mesenteric-like folds or buttresses that anchored the cusps to the vessel wall. These folds extended 50-100 micrometers beyond the cusp margins on the outflow side of the valve. The attachments of the cusps, buttresses, and vessel wall to one another resulted in the formation of postvalvular sinuses, such that raised intraluminal pressure downstream to valve areas would distend the sinuses, causing leaflet apposition and hence valvular closure. The morphology of the valves was such that they were not considered to provide any significant impediment to the antegrade flow of lymph.

Apoprotein a metabolism in tangier disease

Abstract The metabolic defect in Tangier disease has been investigated in two homozygous family members. One patient was pretreated with large amounts of homologous HDL prior to the injection of [ 125 I]HDL and the metabolism of the substituted HDL was analyzed by two-dimensional immunoelectrophoresis employing monospecific antisera against apoproteins A-I and A-II. In addition, the specific activities of the A apoproteins have been determined throughout the course of HDL catabolism. Radioactivity confined to apoproteins A-I and A-II decayed from the plasma monoexponentially with a T 1 2 of 7 h and 17 h, respectively; the specific activity of apoprotein A-I remained unchanged in the course of HDL catabolism, while that of apoprotein A-II constantly decreased. The cellular concentration of the A apoproteins in the epithelial cells of the jejunal mucosa was determined in cryostat sections of intestinal biopsy specimens obtained from the second homozygous Tangier patient and several control patients. Employing the direct immunofluorescence technique and fluorescein isothiocyanate-labeled antibodies (γ-globulins) against apoprotein A-I and apoprotein A-II, intense specific apoprotein A immunofluorescence was detected within the epithelial cells and the collecting lymph vessels of the intestinal mucosa. The pattern of immunofluorescence in the Tangier and control intestinal mucosas was indistinguishable. Thus, the intravascular depletion of the A apoproteins contrasts with their regular cellular concentration. Our studies link the defect in Tangier disease to apoprotein A-I. The inability of this apoprotein to associate with protein and/or lipid and to become a regular constituent of HDL has been identified as the biochemical defect in this disease. This abnormality is currently best explained by a structural mutation or a specific catabolic defect of apoprotein A-I.

Contractile stimuli in collecting lymph vessels.

Contractility was investigated in collecting lymph vessels of rat and guinea pig mesentery. Lymphatic diameter and micropressure were simultaneously recorded under normal conditions and during micromanipulation of intralymphatic pressure. Spontaneous activity involved characteristic changes in intralymphatic pressure coincident with opening and closure of upstream and downstream valves. Contractions were irregular but still predictable by noting the trend of intraluminal pressure as it approached a threshold level. Mechanical obstruction upstream of lymph vessels reduced lymph pressure and contraction frequency. Microinjection or withdrawal of fluid caused contraction frequency. Microinjection or withdrawal of fluid caused contraction frequency to rise and fall, respectively. Contraction rate was not affected by the level of general anesthesia. Lymphatic wall tension, as calculated from pressure-radius variables, correlated well with contraction frequency, suggesting a myogenic origin for the contractile mechanism. However, lymphatic smooth muscle may be inherently unstable since some contractility persists despite an absence of pressure stimuli.

Lymphatic vessels of the dental pulp in dogs.

Lymphatic vessels of the pulp were traced in the teeth of dogs. At the coronal surface the lymph capillaries originated as blind beginnings in the pulp proper near the zone of Weil, whereas they are found adjacent to the odontoblastic layer on the lateral surfaces. These capillaries emptied into collecting lymph vessels that coursed apically to exit through the apical foramens to finally drain into the alveolar lymphatic vessel.

Studies on the biology of the periodontium of marmosets: V. Lymphatic vessels of the periodontal ligament.

Lymphatic vessels of the periodontal ligament were traced in the marmoset. Lymph capillaries originated in the ligament as blind endings and emptied into collecting lymph vessels, which coursed along three pathways in the ligament.