title: Cholinergic innervation of human mesenteric lymphatic vessels.
abstract: BACKGROUND
  The cholinergic neurotransmission within the human mesenteric lymphatic vessels has been poorly studied. Therefore, our aim is to analyse the cholinergic nerve fibres of lymphatic vessels using the traditional enzymatic techniques of staining, plus the biochemical modifications of acetylcholinesterase (AChE) activity.
  
  
  METHODS
  Specimens obtained from human mesenteric lymphatic vessels were subjected to the following experimental procedures: 1) drawing, cutting and staining of tissues; 2) staining of total nerve fibres; 3) enzymatic staining of cholinergic nerve fibres; 4) homogenisation of tissues; 5) biochemical amount of proteins; 6) biochemical amount of AChE activity; 6) quantitative analysis of images; 7) statistical analysis of data.
  
  
  RESULTS
  The mesenteric lymphatic vessels show many AChE positive nerve fibres around their wall with an almost plexiform distribution. The incubation time was performed at 1 h (partial activity) and 6 h (total activity). Moreover, biochemical dosage of the same enzymatic activity confirms the results obtained with morphological methods.
  
  
  CONCLUSIONS
  The homogenates of the studied tissues contain strong AChE activity. In our study, the lymphatic vessels appeared to contain few cholinergic nerve fibres. Therefore, it is expected that perivascular nerve stimulation stimulates cholinergic nerves innervating the mesenteric arteries to release the neurotransmitter AChE, which activates muscarinic or nicotinic receptors to modulate adrenergic neurotransmission. These results strongly suggest, that perivascular cholinergic nerves have little or no effect on the adrenergic nerve function in mesenteric arteries. The cholinergic nerves innervating mesenteric arteries do not mediate direct vascular responses.
authors.forename: V
authors.initials: V
authors.lastname: D'Andrea
authors.forename: E
authors.initials: E
authors.lastname: Bianchi
authors.affiliation: Department of Sensory Organs, Sapienza University of Rome, Rome, Italy. t.samanta@yahoo.it.
authors.forename: S
authors.initials: S
authors.lastname: Taurone
authors.forename: F
authors.initials: F
authors.lastname: Mignini
authors.forename: C
authors.initials: C
authors.lastname: Cavallotti
authors.forename: M
authors.initials: M
authors.lastname: Artico
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D057075:Enzyme Assays; D006801:Humans; D042601:Lymphatic Vessels / Q000166:cytology / Q000294:innervation*; D008643:Mesentery / Q000166:cytology / Q000294:innervation*; D009412:Nerve Fibers / Q000201:enzymology; D013194:Staining and Labeling
chemical_list: D000110:Acetylcholinesterase