Substance P stimulates sphincter of Oddi motility and inhibits trans-sphincteric flow in the Australian brush-tailed possum.
Neurogastroenterol Motil
; 10(2): 165-73, 1998 Apr.
Article
in En
| MEDLINE
| ID: mdl-9614675
ABSTRACT
Substance P containing nerves are widely distributed throughout the gastrointestinal tract. The aims of this study were to determine the distribution of substance P containing nerves in the extrahepatic biliary tree of the Australian brush-tailed possum and to characterize the effect of exogenous substance P on the sphincter of Oddi (SO) motility and transphincteric flow in vivo. Immunohistochemical staining of fixed specimens (n = 8) found moderate numbers of substance P containing nerve cell bodies and fibres throughout the neural plexuses of the SO, in particular in the serosal and intraluminal nerve trunks of the SO and gallbladder. Synthetic porcine substance P (1-2000 ng kg-1), administered by close intra-arterial injection (i.a.; n = 7), produced a dose-dependent elevation in basal pressure [P < 0.01] and an associated dose-dependent reduction in trans-sphincteric flow [P < 0.0001]. Substance P had no significant dose-dependent effect on SO phasic contraction amplitude or frequency. Tetrodotoxin (9 micrograms kg-1, i.a.) did not inhibit the effect of substance P on SO motility and trans-sphincteric flow (n = 5). In conclusion, substance P containing nerves are found throughout the possum extrahepatic biliary tree. Exogenous substance P stimulates SO motility and reduces trans-sphincteric flow in vivo by acting directly on the sphincter smooth muscle.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bile
/
Substance P
/
Gallbladder Emptying
/
Neurons
/
Sphincter of Oddi
Limits:
Animals
Country/Region as subject:
Oceania
Language:
En
Journal:
Neurogastroenterol Motil
Journal subject:
GASTROENTEROLOGIA
/
NEUROLOGIA
Year:
1998
Document type:
Article
Affiliation country:
Australia