Lymphatic drainage from the ventricular septum to the atrioventricular node in human beings.

It has been suggested that intracardiac lymphatics may play a role in the pathophysiologic processes involving the conduction system. To test the possibility of linkage between the ventricular septum and the atrioventricular (AV) node, india ink was injected into the ventricular septum of freshly removed human hearts. Microscopic sections of the AV node and adjacent tissue were examined for the presence of india ink. India ink was seen in and near the AV node in lymphatic channels and small veins. The implication is that potentially noxious materials can be transmitted by lymphatics from remote areas and influence adjacent conduction system fibers. Thus, it is possible that AV conduction disturbances after myocardial infarction may be induced by a lymphatic mechanism.

Direct cannulation and injection lymphangiography of the canine cardiac and pulmonary efferent mediastinal lymphatics in experimental congestive heart failure.

Lymphangiograms were made in dogs with experimental congestive heart failure by cannulation of the left cardiac efferent (LCE), left pulmonary efferent (LPE), or cardiopulmonary lymphatic and injection of radiopaque medium. The lymphoangiograms showed cardiac enlargement and dilated mediastinal lymphatic channels consistent with an increase in lymph flow. By consecutive injections in the LCE and LPE, wer demonstrated that a common channel, the cardiopulmonary lymphatic, is opacified by injection in either the LPE or LCE. This common channel has been called the "cardiac lymphatic" and used for the collection of "cardiac" lymph. The authors' experiments suggest that this cardiopulmonary lymphatic carries both cardiac and pulmonary lymph.

Application of direct cannulation and injection lymphangiography to the study of the canine cardiac and pulmonary efferent mediastinal lymphatics.

Lymphangiograms of canine cardiac and pulmonary efferent mediastinal lymphatics were made by cannulation and injection of Ethiodol. Injections were made singly and serially. The mediastinal lymphatics and lymph nodes, which constitute the pathways of drainage of the heart and lungs, were delineated from the point of cannulation to the right and left inferior cervical region where the right lymphatic duct and thoracic duct are located. Lymphangiography reveals that the lymphatics which drain the heart and lungs may join to form common mediastinal lymphatic channels. Interconnections between mediastinal channels were demonstrated. The lymphatics terminated in the region of both the right lymphatic duct and thoracic duct in every subject. The so-called "cardiac node of Drinker" is usually a group of pretracheal nodes rather than a single node. The pretracheal nodes and those more cephalad receive drainage of lymph from both the heart and lungs. These studies suggest that lymph collected by cannulation of a "cardiac" lymphatic adjacent to the "cardiac node" will contain pulmonary as well as cardiac lymph. Thus the high flows reported by many investigators for "cardiac" lymph probably indicates that pulmonary lymph is mixed with cardiac lymph, and that the experimental data should be interpreted with this in mind.

Thoracic duct and right lymphatic duct: surgical approaches for drainage in the canine with comparison of cellular and chemical contents.

The technics of drainage of the right lymphatic duct (RD) and thoracic duct (TD) used in our laboratory have been described and illustrated. In two series of experiments the components of RD and of TD lymph were compared to blood plasma collected concurrently. RD and TD lymph, collected concurrently, were also compared in a third series. RD and TD lymph differ in a number of ways including rate of flow, enzyme activity, cell count and lipid-electrophoretic patterns. The limitations of RD lymph for the study of fluid and protein dynamics of the lungs and the cell population of lung lymph are outlined. Higher levels of enzyme activity in RD compared to TD lymph have been noted. This phenomena appears to depend on a number of complex factors.

Lymphatics of the canine papillary muscles.

A relatively dense concentration of lymphatics in the region of the papillary muscles of the canine left ventricle has been described. It is suggested that these channels may play a role in the development of pathologic changes affecting the mitral valve apparatus which could subsequently cause valve dysfunction.

Alternative pathways for drainage of cerebrospinal fluid in the canine brain.

Although the brain has no formal lymphatic system, a substantial quantity of cerebrospinal fluid (CSF) has nonetheless been shown to drain via cervical lymphatics. To pursue further the issue of alternative drainage pathways for CSF, we infused a solution of Ringer's lactate (RL) into the cisterna magna of the dog brain and monitored both the flow and concentration of total protein of cervical lymph. This maneuver promoted a nearly three-fold rise in intracranial pressure and was accompanied by a rise in cervical lymph flow and fall in its protein content. In addition, a profuse nasal discharge (11.4 ml/hr) developed with a moderately high protein content of the rhinorrhea fluid (1.8 g/dl), along with similar appearance times of Evans blue dye (instilled in the cisterna magna) in both cervical lymph and the rhinorrhea fluid (48-70 minutes after infusion). These findings suggest alternative drainage pathways for CSF besides the arachnoid villi (Pacchionian bodies) including connections with lymphatics in the neck and along the olfactory nerve, and around the cribiform plate to the nasal submucosa, and with proptosis, perhaps also through the aqueous humor-canal of Schlemm and nasolacrimal duct.

T-lymphocytes in venous blood and lymph from the thoracic duct and right lymphatic duct of normal dogs.

The WBC and per cent polymorphonuclear cells in blood increased significantly during the approximately 3 hours of the experiments. The number of lymphocytes did not change significantly. Corresponding cellular components in RD and TD lymph were not significantly different. The per cent of T-rosettes in FVB was more than three times that in RD and TD lymph (33/10). T-rosettes were predominantly formed by medium lymphocytes (68-82%) in both blood and lymph.

Lymphatic pathways and rate of absorption of 131I-albumin from pericardium of dogs.

Labeled albumin diluted to 4.0 ml with normal saline solution was instilled into the pericardium of 14 dogs. Lymph from the right lymphatic duct (RD) and thoracic duct (TD) was collected at intervals as well as blood samples, and radioactivity measured.

T-lymphocytes in experimental myocardial infarction.

The WBC count, percentage of PMN's, lymphocyte counts and percentage of T-cells in blood, right duct and thoracic duct lymph of three- and nine-day post-coronary ligation and corresponding sham dogs were studied. It was observed that the percentage of T-cells in the right duct lymph of the nine-day post-coronary ligation group was significantly increased compared to the sham group, suggesting a possible cellular immune response late in the infarction process.

Canine cardiac lymph potassium, pH and flow after experimental myocardial infarction.

Canine cardiac lymph was studied after acute experimental myocardial infarction. The lymph potassium concentration remained the same, the lymph potassium content increased, the lymph pH decreased, and the lymph flow increased while the serum potassium and pH remained the same. It is suggested that localized hypoxia may result in cellular changes that release substances, e.g., potassium, to the interstitial space where they mobilize fluid and enhance lymph flow.

A method for the collection of pure pulmonary lymph in the canine.

An original method for the collection of pure or nearly pure pulmonary lymph in the canine is desirable for the study of pulmonary water, protein dynamics and cells. Right lymphatic duct lymph has been used extensively but it known to contain lymph from a number of extrapulmonary sources and has been altered by passage through lymph nodes. Pulmonary lymph was collected from 13 dogs through an open chest. The mean flow of lymph was 1.5 milliliters per hour +/- 0.08. This flow is compared with 3.7 milliliters per hour from the right lymphatic duct and 22.5 milliliters per hour from the thoracic duct in a group of dogs with a closed chest. The levels of lactate dehydrogenase--634 units per liter--and glutamic-oxalacetic transaminase--416 units per liter--in pure pulmonary lymph were much higher than in right lymphatic duct lymph--lactate dehydrogenase 125 units per liter; glutamic-oxalacetic transaminase 94.0 units per liter, in thoracic duct lymph--lactate dehydrogenase 47 units per liter; glutamic-oxalacetic transaminase 80.5 units per liter--and in blood plasma--lactate dehydrogenase 299 units per liter; glutamic-oxalacetic transaminase 95 units per liter. Low levels were noted in Na+, 107, and Cl-, 85, in pure pulmonary lymph versus plasma--Na+ 145; Cl- 112, right lymphatic duct lymph--Na+ 146; Cl- 115, and thoracic duct lymph--Na+ 146; Cl- 114. The method can be adapted for prolonged drainage in conscious dogs, which would enhance its usefulness.