TY - JOUR

T1 - The human thoracic duct is functionally innervated by adrenergic nerves

AU - Telinius, Niklas

AU - Baandrup, Ulrik

AU - Rumessen, Jüri

AU - Pilegaard, Hans

AU - Hjortdal, Vibeke

AU - Aalkjaer, Christian

AU - Boedtkjer, Donna Briggs

PY - 2014/1/15

Y1 - 2014/1/15

N2 - 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.

AB - 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.

KW - Adrenergic Agents/pharmacology

KW - Adrenergic Fibers/drug effects

KW - Aged

KW - Electric Stimulation

KW - Female

KW - Humans

KW - Isometric Contraction

KW - Male

KW - Middle Aged

KW - Sympathetic Nervous System/drug effects

KW - Sympathomimetics/pharmacology

KW - Thoracic Duct/innervation

U2 - 10.1152/ajpheart.00517.2013

DO - 10.1152/ajpheart.00517.2013

M3 - Journal article

C2 - 24213615

VL - 306

SP - H206-13

JO - A J P: Heart and Circulatory Physiology (Online)

JF - A J P: Heart and Circulatory Physiology (Online)

SN - 1522-1539

IS - 2

ER -