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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-10-23
pubmed:abstractText
Because of the low basal output, measurement of acetylcholine (ACh) release from enteric neurons usually requires cholinesterase inhibition, a condition which is known to interfere with feed-back mechanisms regulating ACh release. In this study, we resorted to a highly sensitive HPLC-ED method to determine the minimum requirement of physostigmine to achieve reliable quantitation of spontaneous endogenous ACh overflow from the guinea-pig isolated colon. Furthermore, in order to assess the degree of interference by physostigmine with cholinergic function, we assessed the effect of scopolamine and oxotremorine (in the presence of physostigmine) on spontaneous ACH overflow (to detect the presence of autoreceptors) and also measured the efficiency of the peristaltic reflex with different physostigmine concentrations. Spontaneous endogenous ACh overflow was detectable only with physostigmine concentrations > or = 10 nM. ACh overflow increased with increasing physostigmine concentrations (10 nM-10 microM range). Scopolamine significantly enhanced the facilitatory effect of physostigmine concentrations > or = 10 nM; conversely, oxotremorine inhibited ACh overflow. Peristaltic efficiency was not significantly affected by physostigmine concentrations < or = 300 nM. In conclusion, this modified HPLC-ED method allows ACh detection with minimal physostigmine concentrations (10-30 nM), which do not interfere with peristaltic activity, do not saturate autoreceptor feed-back mechanisms and therefore improve the assessment of cholinergic function in colonic enteric neurons.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0304-3940
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
232
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9-12
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Acetylcholine detection by a modified HPLC-ED method improves the assessment of cholinergic function in the myenteric plexus of the guinea-pig colon.
pubmed:affiliation
Department of Internal Medicine and Therapeutics, II Faculty of Medicine, University of Pavia, Varese VA, Italy.
pubmed:publicationType
Journal Article