RT Journal Article
SR Electronic
T1 Inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the Australian Brush-tailed possum (<em>Trichosurus vulpecula</em>)
JF Gut
JO Gut
FD BMJ Publishing Group Ltd and British Society of Gastroenterology
SP 692
OP 698
DO 10.1136/gut.49.5.692
VO 49
IS 5
A1 Meedeniya, A C B
A1 Al-Jiffry, B O
A1 Konomi, H
A1 Schloithe, A C
A1 Toouli, J
A1 Saccone, G T P
YR 2001
UL http://gut.bmj.com/content/49/5/692.abstract
AB BACKGROUND Gall bladder functions are modulated by neurones intrinsic to the organ. Data are available on the neurochemical composition of intrinsic and extrinsic nerves innervating the gall bladder but are lacking on specific functional classes of gall bladder neurones.AIMS To characterise the intrinsic motor neurones of the gall bladder and identify their roles using pharmacological techniques.METHODS Retrograde tracing from the possum gall bladder muscle in vitro allowed identification of intrinsic motor neurones. Subsequently, their content of choline acetyltransferase and nitric oxide synthase, markers of acetylcholine and nitric oxide containing neurones, was established using immunohistochemical techniques. Organ bath pharmacology was used to evaluate neurotransmission by acetylcholine and nitric oxide in gall bladder muscle strips.RESULTS Innervation of the gall bladder musculature by neurones of both the muscular and serosal plexuses was demonstrated. A large proportion (62%) of these motor neurones were immunoreactive for nitric oxide synthase. All gall bladder neurones showed immunoreactivity for choline acetyltransferase. Organ bath pharmacology confirmed the neuroanatomical data, showing acetylcholine and nitric oxide mediating neurotransmission to the gall bladder musculature.CONCLUSIONS Neurones containing acetylcholine and nitric oxide, located within the muscular and serosal plexuses, provide excitatory and inhibitory motor innervation of the gall bladder, respectively. The large inhibitory innervation suggests active relaxation of the gall bladder during filling, mediated by intrinsic nerves.AChacetylcholineCCK-8cholecystokinin octapeptideChATcholine acetyltransferaseDiI1′-didodecyl-3,3,3′3′-tetra-methyl-indocarbocyanine perchlorateEFSelectrical field stimulationl-NAMEN omega-nitro-l-arginine methyl esterNANCnon-adrenergic non-cholinergicNOnitric oxideNOSnitric oxide synthaseTTXtetrodotoxinVIPvasoactive intestinal polypeptide