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PubMed · 9663721

Nitric oxide and gall-bladder motor function.

W Luman·J E Ardill·E Armstrong·G D Smith·L Brett·A M Lessells·W G Haynes·G A Gray·E J Mickley·D J Webb·K R Palmer
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Abstract

BACKGROUND: The L-arginine: nitric oxide (NO) pathway has been shown to be important in the regulation of intestinal motility and NO may be the mediator for nonadrenergic noncholinergic (NANC) neurotransmission. AIM: To determine the role of the L-arginine: NO pathway in gall-bladder motor function. METHODS: Strips of fresh bovine and human gall-bladders were stimulated with cholecystokinin (CCK). The effects of glyceryl trinitrate (GTN), sodium nitroprusside and Kreb's solution upon CCK-stimulated muscle contraction were examined. The effect of the NO synthase inhibitor, L-NG-monomethyl-arginine (L-NMMA) upon basal muscle tone was also examined. Ten human gall-bladders were immunohistochemically stained for nitric oxide synthase (NOS) and product 9.5 to identify neurones. Postprandial gall-bladder emptying was measured on separate occasions in six healthy volunteers during systemic intravenous infusion of normal saline; glyceryl trinitrate; sodium nitroprusside (SNP), hydralazine and L-NMMA. RESULTS: In the in vitro study, GTN and SNP significantly reduced the tension of CCK-stimulated muscle contraction whilst Kreb's solution had no effect. L-NMMA increased tonic and phasic muscle contractions. Immunohistochemical staining for NOS was consistently absent in human gall-bladders. In the in vivo study, both GTN and SNP caused significant impairment of gall-bladder emptying; the ejection fraction was only 50% at the end of the study period involving these infusates, this contrasted with ejection fractions in excess of 80% during infusions with hydralazine, saline and L-NMMA. CONCLUSION: Pharmacological doses of NO donors impair postprandial gall-bladder emptying in vivo and relax gall-bladder smooth muscle in vitro. However, negative immunohistochemical staining suggest NOS is unlikely to be the neurotransmitter for NANC innervation regulating gall-bladder motility.

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AdultAnimalsBlood PressureCattleEnzyme InhibitorsGallbladderGallbladder EmptyingGastrointestinal HormonesHeart RateHumansImmunohistochemistryIn Vitro TechniquesMaleNitric OxideNitric Oxide SynthasePostprandial Periodomega-N-MethylarginineClinical TrialJournal Article

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W Luman, J E Ardill, E Armstrong, G D Smith, L Brett, A M Lessells, W G Haynes, G A Gray, E J Mickley, D J Webb, K R Palmer. 1998. Nitric oxide and gall-bladder motor function.. https://doi.org/10.1046/j.1365-2036.1998.00322.x

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