Neurogenic Control of the Ovine Gallbladder: Ultrastructural and Functional Study

Khoursheed, Moussa; Krajčí, D; Oriowo, Mabayoje A.; Kadavil, Elizabeth A.; Philip, Elizabeth; Thulesius, Olav

doi:10.1159/000007512

Cited by 7 publications

(9 citation statements)

References 24 publications

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“…Previous pharmacological data support our finding, showing a neurally mediated inhibition of the gall bladder musculature by NO 1314 This was initially demonstrated in vitro using human gall bladder muscle strips where TTX sensitive, EFS evoked relaxations were blocked by l -nitroarginine 13. More recent studies have demonstrated a similar mechanism in the guinea pig,24sheep,14 and human25 gall bladder.…”

Section: Discussionsupporting

confidence: 88%

“…14 This was initially demonstrated in vitro using human gall bladder muscle strips where TTX sensitive, EFS evoked relaxations were blocked by l -nitroarginine 13. More recent studies have demonstrated a similar mechanism in the guinea pig,24sheep,14 and human25 gall bladder. Notably, these studies did not characterise the source of the inhibitory innervation.…”

Section: Discussionmentioning

confidence: 92%

“…14 Studies in vivo have also shown involvement of NO in gall bladder relaxation 15. Similarly, contraction of the gall bladder involves a cholinergic mechanism 16.…”

mentioning

confidence: 99%

“…Similarly, contraction of the gall bladder involves a cholinergic mechanism 16. Electron microscopy has shown the presence of nerve varicosities containing clear and large dense cored vesicles in close apposition to the gall bladder muscle 14. However, the neurochemicals present within these nerves were not investigated.…”

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confidence: 99%

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Inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the Australian Brush-tailed possum (Trichosurus vulpecula)

Meedeniya

Al-Jiffry²,

Konomi³

et al. 2001

Gut

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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. (Gut 2001;49:692-698)

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 92%

“…14 Studies in vivo have also shown involvement of NO in gall bladder relaxation 15. Similarly, contraction of the gall bladder involves a cholinergic mechanism 16.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the Australian Brush-tailed possum (Trichosurus vulpecula)

Meedeniya

Al-Jiffry²,

Konomi³

et al. 2001

Gut

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“…Therefore, more careful pharmacological analyses should be performed to establish the role of muscarinic receptor subtypes on the MR. The inhibitory action of hexamethonium can be exerted due to its binding to nicotinic receptors present in the gallbladder ganglia (Khoursheed et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

Characteristics and Cholinergic Control of the ‘Minute Rhythm’ in Ovine Antrum, Small Bowel and Gallbladder

Kw¹

2002

Journal of Veterinary Medicine Series A

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Eight adult conscious rams were used to characterize further the minute rhythm and to determine the role of cholinergic receptors in nervous control of this event. In chronic experiments, the myoelectrical and motor activity of the gastrointestinal tract and gallbladder were recorded. Physiological experiments were performed in fasted or non-fasted rams before, during and after feeding, and the occurrence of minute rhythm during various phases of the migrating motor myoelectric complex was observed. The pattern occurred most frequently in the small intestine, where it exhibited mostly the propagating character. It was also detectable in the ileum. In the gallbladder, the minute rhythm arrived systematically and its character was irregular, propagating, retropropagating or stationary. In all episodes observed, it was well correlated with that in the small intestine. In the pyloric antrum, the minute rhythm was identified occasionally. During pharmacological experiments, 0.15 M NaCl or graded doses of hexamethonium, atropine and pirenzepine were administered intravenously during various phases of the migrating motor myoelectric complex, in fasted and non-fasted animals, before and during feeding. The drugs inhibited the minute rhythm in the small bowel for a longer period than in the gallbladder. However, the smallest dose of pirenzepine (0.02 mg/kg) exerted a non-significant effect both in the small intestine and in the gallbladder. It is concluded, that in normal conditions the minute rhythm occurs regularly in the entire small intestine and in the gallbladder. In the small intestine the pattern is organized more precisely. The minute rhythm is controlled by nicotinic receptors and by muscarinic receptor subtypes.

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Innervation of the extrahepatic biliary tract

2004

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The extrahepatic biliary tract is innervated by dense networks of extrinsic and intrinsic nerves that regulates smooth muscle tone and epithelial cell function of extrahepatic biliary tree. Although these ganglia are derived from the same set of precursor neural crest cells that colonize the gut, they exhibit structural, neurochemical, and physiological characteristics that are distinct from the neurons of the enteric nervous system. Gallbladder neurons are relatively inexcitable, and their output is driven by vagal inputs and modulated by hormones, peptides released from sensory fibers, and inflammatory mediators. Gallbladder neurons are cholinergic and they can express a number of other neural active compounds, including substance P, galanin, nitric oxide, and vasoactive intestinal peptide. Sphincter of Oddi (SO) ganglia, which are connected to ganglia of the duodenum, appear to be comprised of distinct populations of excitatory and inhibitory neurons, based on their expression of choline acetyltransferase and substance P or nitric oxide synthase, respectively. While SO neurons likely receive vagal input and their activity is modulated by release of neuropeptides from sensory fibers, a significant source of excitatory synaptic input to these cells arise from the duodenum. This duodenum-SO circuit is likely to play an important role in the coordination of SO tone with gallbladder motility in the process of gallbladder emptying. Now that we have gained a relatively thorough understanding of the innervation of the biliary tree under healthy conditions, the way is paved for future studies of altered neural function in biliary disease.

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Neurogenic Control of the Ovine Gallbladder: Ultrastructural and Functional Study

Cited by 7 publications

References 24 publications

Inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the Australian Brush-tailed possum (Trichosurus vulpecula)

Inhibitory motor innervation of the gall bladder musculature by intrinsic neurones containing nitric oxide in the Australian Brush-tailed possum (Trichosurus vulpecula)

Characteristics and Cholinergic Control of the ‘Minute Rhythm’ in Ovine Antrum, Small Bowel and Gallbladder

Innervation of the extrahepatic biliary tract

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