The human thoracic duct is functionally innervated by adrenergic nerves.

Lymphatic vessels from animals have been shown to be innervated. While morphological studies have confirmed human lymphatic vessels are innervated, functional studies supporting this are lacking. The present study demonstrates a functional innervation of the human thoracic duct (TD) that is predominantly adrenergic. TDs harvested from 51 patients undergoing esophageal and cardia cancer surgery were either fixed for structural investigations or maintained in vitro for the functional assessment of innervation by isometric force measurements and electrical field stimulation (EFS). Electron microscopy and immunohistochemistry suggested scarce diffuse distribution of nerves in the entire vessel wall, but nerve-mediated contractions could be induced with EFS and were sensitive to the muscarinic receptor blocker atropine and the α-adrenoceptor blocker phentolamine. The combination of phentolamine and atropine resulted in a near-complete abolishment of EFS-induced contractions. The presence of sympathetic nerves was further confirmed by contractions induced by the sympathomimetic and catecholamine-releasing agent tyramine. Reactivity to the neurotransmitters norepinephrine, substance P, neuropeptide Y, acetylcholine, and methacholine was demonstrated by exogenous application to human TD ring segments. Norepinephrine provided the most consistent responses, whereas responses to the other agonists varied. We conclude that the human TD is functionally innervated with both cholinergic and adrenergic components, with the latter of the two dominating.

Analysis of nerve supply pattern in thoracic duct in young and elderly men.

BACKGROUND: Analysis of the innervation pattern of the thoracic duct in young and elderly human subjects has been performed. The subdivision of the vessels in cervical and lumbar region were taken in consideration. METHODS AND RESULTS: Immunostaining for general nerve fibers with a PGP 9.5 marker disclosed a diffuse innervation of the thoracic duct in young subjects, which was strongly reduced in elderly subjects. In young subjects, tyrosine hydroxylase (TH) and neuropeptide Y (NPY) immunoreactive fibers, markers of noradrenergic postganglionic sympathetic fibers, were frequent; choline acetyltransferase (ChAT) immunoreactive fibers, marker of cholinergic parasympathetic nerve fibers, were also well represented. Therefore, the influence of sympathetic and parasympathetic nerve systems on the thoracic duct can be confirmed. The immunoreactivity of vasoactive intestinal peptide (VIP), a neuropeptide frequently present in cholinergic parasympathetic nerve fibers, was scarcely present. Dopamine-positive fibers were observed in few short nerve fibers. Substance P (SP)-positive fibers were widely distributed in the medial and intimal smooth muscle layers, suggesting their involvement as contractile modulating fibers and sensitive fibers. In elderly subjects, an evident reduction of all specific nerve fibers analyzed was detected, the ChAT-positive fibers being the most affected. CONCLUSIONS: The lymphatic vessel thoracic duct is able to regulate hydrodynamic lymph flow by intrinsic contraction of its smooth muscle layer. Therefore, analysis of the thoracic duct innervation pattern may be important in assessing the regulation of vessel contraction. These findings called attention to the reduction of lymphatic drainage functionality affecting fluid balance in the elderly.

A rare Lymphatico-Venous communication associated with duplication of thoracic duct

RESUMEN: Una inusual presentación de duplicación del conducto torácico con una rara comunicación linfático-venosa, fue encontrada durante una disección de rutina, por estudiantes de pregrado. El conducto torácico se encuentra duplicado a nivel de la vértebra T12. Normalmente el conducto torácico se abre en la unión de la venas yugular interna izquierda y subclavia izquierda. En el lado derecho del cuello, el conducto linfático derecho recibe la linfa de la parte derecha de la cabeza y del cuello, del miembro superior derecho y lado derecho del tórax. El conducto torácico duplicado en el lado izquierdo se abrió directamente en la vena cava inferior. Este caso es discutido con respecto a su desarrollo, incidencia y significación clínica.

[Adrenergic innervation of lymph nodes and the thoracic duct]. / Adrenergicheskaia innervatsiia limfaticheskikh uzlov i grudnogo protoka.

By means of incubation of slices in 2% solution of glyoxylic acid distribution of adrenergic fibers in the rabbit lymph nodes and in the thoracic lymphatic duct has been studied. Adrenergic fibers get into parenchyma of the lymph nodes via two ways. The first--the perivascular, when the nervous fibers make a plexus and get into the node along the blood vessels, the second--diffuse nervous fibers get together with trabecules in between the lymphoid nodules. The distribution density of the adrenergic fibers is not the same in different groups of the lymph nodes. In the lumbar nodes it is the highest. In the lymph nodes of the cervical part the density of the sympathetic fibers is, as a rule, lower than in the lumbar, but higher than in the axillary nodes. The lowest density of th adrenergic fibers is in the mesenteric, superficial inguinal lymph nodes and in the lymph nodes, situating near the thoracic part of the aorta. In the lymphatic duct wall small amount of adrenergic fibers are revealed, they form a plexus, predominantly in the cranial part.

[Catecholamine content in the wall of the thoracic duct of the dog during postnatal development]. / Soderzhanie katekholaminov v stenke grudnogo limfaticheskogo protoka sobaki v protsesse postnatal'nogo razvitiia.

Studies have been made on the content of catecholamines (norepinephrine, adrenaline, dihydroxyphenylalanine) in the wall of the thoracic lymphatic duct of puppies during their first 3 months of postnatal life. It was found that within this period, the content of norepinephrine increases, that of adrenaline remains unchanged, whereas dihydroxyphenylalanine is detected only in animals of the first month. The increase in norepinephrine content indicates gradual maturation of the adrenergic innervation in the wall of the lymphatic duct.

[Development of sympathetic influences on lymph flow in the postnatal ontogeny of dogs]. / Razvitiie simpatcheskikh vliianii na limfotok v postnatal'nom ontogeneze u sobak.

Studies have been made on functional development of influences of the splanchnic nerve upon the lymph flow in puppies. It was shown that during the first week of postnatal life of puppies, the thoracic duct functionally is not yet ready to participate in vasomotor reactions of the organism to stimulation of the splanchnic nerve. Active role of the thoracic duct in vasomotor reactions to stimulation of the splanchnic nerve was initially noted after the first week of postnatal life of animals.

Evidence for alpha-adrenergic innervation of the isolated canine thoracic duct.

The excitatory innervation of isolated thoracic duct segments was studied using tissue bath techniques. No spontaneous activity was present in longitudinal or helical strips obtained from a portion of the thoracic duct cephalad to the hilum of the lung. Norepinephrine (10(-8) to 10(-5) M) and tyramine (3 x 10(-5) M) produced contractions that were antagonized by phentolamine (2 x 10(-5) M) and phenoxybenzamine (10(-7) M). Acetylcholine (10(-7) to 10(-4) M) produced contractions that were antagonized by atropine (5 x 10(-9) M). Thoracic duct strips also contracted in response to field electrical stimulation, and maximal responses were obtained with a stimulus of 15 V, 15 Hz, and 1-ms pulse duration. These electrically induced contractions were abolished by tetrodotoxin (5 x 10(-7) M), phentolamine (2 x 10(-5) M), phenoxybenzamine (10(-7) M), and guanethidine (3 x 10(-6) M), but not by atropine (10(-6) M). We conclude that smooth muscle of the canine thoracic duct contains alpha-adrenergic and acetylcholine receptors, both of which cause contraction when stimulated. However, only the alpha-receptors appear to be innervated.

[Structure of the wall of thoracic lymphatic duct of dogs in postnatal ontogeny]. / Izuchenie stroeniia stenki grudnogo limfaticheskogo protoka u sobak v postnatal'nom ontogeneze.

Light and electronmicroscopic studies have been made on the structure of the wall of the thoracic lymph duct in puppies within 3 months of their postnatal life. It was shown that differentiation and specialization of the smooth muscle cells is accomplished in the main features to the 3rd month of postnatal life. Within this period, the number of the nervous fibers increases, and their linking to the media becomes more close. Absence of dense neuro-muscular contacts indicates distant pattern of the effect of neuromediators on the effector cells. The data obtained demonstrate that during postnatal ontogenesis of dogs changes take place in the barrier properties of the wall of the lymph duct, as well as the formation of morphological substrate for active contractile activity.

[The adrenergic innervation of the thoracic lymphatic duct in dogs in postnatal ontogeny]. / Adrenergicheskaia innervatsiia grudnogo limfaticheskogo protoka u sobak v postnatal'nom ontogeneze.

Using histochemical fluorescence technique, studies have been made on the adrenergic innervation of the wall of the thoracal lymphatic duct in postnatal development of puppies. Adrenergic fibers were found in the adventitial layer of the duct. During postnatal development of the animals, adrenergic innervation of this duct becomes more perfect, reaching the level of adult animals to the age of 2-3 months.