-transparent.png){kind=logo}
To evaluate if L-arginine-nitric oxide-pathways are involved in the neural relaxation of the sphincter of Oddi, we studied the effect of nitric oxide synthase inhibition on electrical field stimulation-induced relaxation of the sphincter of Oddi in the guinea pig in vitro. After incubation with atropine (1 microM), phentolamine (1 microM) and propranolol (1 microM), histamine (50 microM) and cholecystokinin-octapeptide (25 nM) produced similar increases in sphincter tone. Subsequent field stimulation induced sphincteric relaxation, that was significantly greater when the initial tone had been raised by cholecystokinin (5 Hz, 59 +/- 9%; 10 Hz, 79 +/- 9%) compared to histamine (5 Hz, 27 +/- 3%; 10 Hz, 40 +/- 7%). N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 microM), which competitively inhibits nitric oxide synthase, markedly suppressed this relaxation. The subsequent addition of L-arginine (1 mM), but not D-arginine (1 mM), restored the relaxation. Hexamethonium (100 microM) did not affect the relaxation, but tetrodotoxin (1 microM) completely abolished it. Sodium nitroprusside caused a dose-dependent relaxation of the sphincter (ED50 13 nM), which was unaffected by L-NAME. In conclusion, endogenous nitric oxide synthase products represent a major transmitter of non-adrenergic non-cholinergic relaxation of the sphincter of Oddi in the guinea pig. This relaxation is partially facilitated by cholecystokinin.
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
February 1992,
Gastroenterology,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
March 1998,
Digestive diseases and sciences,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
April 1994,
European journal of pharmacology,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
September 2003,
The British journal of surgery,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
September 1991,
British journal of pharmacology,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
April 1998,
Journal of autonomic pharmacology,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
December 1993,
Acta physiologica Scandinavica,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
January 1993,
American journal of surgery,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
November 1993,
Gastroenterology,
J G Pauletzki, and
K A Sharkey, and
J S Davison, and
A Bomzon, and
E A Shaffer
July 1993,
The Journal of pharmacology and experimental therapeutics,
