title: Vasa nervorum in rat major pelvic ganglion are innervated by nitrergic nerve fibers.
abstract: BACKGROUND
  The vasa nervorum comprises a network of small diameter blood vessels that provide blood supply to nerves and ganglia. The cell bodies of autonomic nerves innervating the urogenital organs are housed in the major pelvic ganglia (MPG) in rats. The vasa nervorum of rat MPG have not been characterized previously, and it is not known whether these blood vessels are innervated by neuronal nitric oxide synthase (nNOS) containing nitrergic nerves.
  
  
  OBJECTIVE
  To characterize the blood vessels in and around the rat MPG and to assess their nitrergic innervation.
  
  
  METHODS
  Characterization of small blood vessels in and around the rat MPG and expression of nNOS in nerve fibers around those blood vessels.
  
  
  METHODS
  MPG were obtained from healthy Sprague Dawley rats, fixed in paraformaldehyde, frozen and sectioned using a cryostat. The blood vessels and their nitrergic innervation were assessed with immunohistochemistry using antibodies against alpha-smooth muscle actin (smooth muscle marker), CD31 (endothelial marker), collagen IV (basal membrane marker) and nNOS. The immunofluorescence was imaged using a laser scanning confocal microscope.
  
  
  RESULTS
  The neuronal cell bodies were contained within a capsule in the MPG. Blood vessels were observed within the capsule of the MPG as well as outside the capsule. The blood vessels inside the capsule were CD31-positive capillaries with no smooth muscle staining. Outside the capsule capillaries, arterioles and venules were observed. The extra-capsular arterioles and venules, but not the capillaries were innervated by nNOS-positive nerve fibers.
  
  
  CONCLUSIONS
  This study, to our knowledge, is the first to demonstrate the blood vessel distribution pattern and their nitrergic innervation in the rat MPG. While similar studies in human pelvic plexus are warranted, these results suggest that the blood flow in the MPG may be regulated by nitrergic nerve fibers and reveal a reciprocal relationship between nerves and blood vessels.
authors.affiliation: Cranfield Health, Cranfield University, Cranfield, Bedfordshire, UK.
authors.forename: Karl A
authors.initials: KA
authors.lastname: Beetson
authors.forename: Stephanie F
authors.initials: SF
authors.lastname: Smith
authors.forename: Asif
authors.initials: A
authors.lastname: Muneer
authors.forename: Norman E
authors.initials: NE
authors.lastname: Cameron
authors.forename: Mary A
authors.initials: MA
authors.lastname: Cotter
authors.forename: Selim
authors.initials: S
authors.lastname: Cellek
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D017950:Ganglia, Sensory / Q000098:blood supply*; D006801:Humans; D007001:Hypogastric Plexus / Q000098:blood supply*; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000378:metabolism; D009412:Nerve Fibers / Q000502:physiology*; D026602:Nitrergic Neurons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014650:Vasa Nervorum / Q000294:innervation*
chemical_list: D000199:Actins; C498862:Acta2 protein, rat
keywords: Autonomic; Autonomic Nerves; Erectile Dysfunction; Lower Urinary Tract Symptoms; Nitrergic; Nitric Oxide; Urogenital; nNOS