Enhancement of XXXX intestinal peristalsis by blockade of muscarinic M1-receptors.

@entity1246 @entity1027 @entity840 @entity6116 @entity1510 @entity4140 @entity5591
1. The effects of @entity4140 and @entity5591 on the peristaltic reflex were investigated in the @entity840 isolated small intestine. Peristalsis was induced by raising the intraluminal pressure and the volume of fluid propelled was taken as a measure of the efficiency of peristaltic activity. 2. Low concentrations of @entity4140 (0.1-1 nM) and of @entity5591 (0.01 nM) significantly enhanced peristalsis, whereas larger concentrations of both drugs caused inhibition. @entity4140 was about 6 times less potent than @entity5591 in increasing peristalsis, but was about 100 times less potent in inhibiting it. 3. Neither @entity6116 (1 microM) nor @entity1510 (0.3 microM) affected the stimulatory action of @entity4140 on peristalsis. 4. @entity1027 increased the efficiency of peristalsis at concentrations of 1 microM and 10 microM; at 10 nM, @entity1027 reduced significantly the increase of peristalsis by @entity4140 . @entity1246 ( @entity1246 ) did not affect peristaltic activity, but the stimulatory effect of @entity4140 was abolished in the presence of 100 microM @entity1246 . 5. The results indicate that activation of neuronal M1-receptors causes inhibition of small intestinal peristalsis. Bicuculline-sensitive 'GABAergic' synapses are probably involved in this inhibition.
