Effect of nitric oxide on propagated clusters of spontaneous motor waves in an ex vivo rabbit intestinal preparation.
The aim of this study was to determine whether nitric oxide can play a role in regulating the propagation of spontaneous motor activity in a rabbit intestinal preparation completely excluded from any central and vascular connection. Experiments were done on nine rabbits of either sex, weighing 2.5 +/- 0.5 kg (mean +/- SD). After one week of semiliquid diet the animals were sacrificed and a segment including the stomach, duodenum and part of the jejunum was removed and placed into a single chamber organ bath containing 1 L of oxygenated Krebs' solution. Four strain gauges connected to a Dynograph Recorder were sutured on the serosal surface 10 cm apart starting from the gastric antrum to the distal duodenum. Once the motor activity was stabilized, N-nitro-L-arginine methyl-ester (L-NAME) was added to the bath at increasing concentration from 10(-7) to 10(-4) M. Spontaneous motor activity was recorded, characterized by the cycling occurrence of bursts of waves, starting from the stomach and propagating to the descending duodenum. L-NAME at higher concentrations reduced the time interval between the bursts of waves with a concomitant increase in the propagation velocity of the motor activity. No change in the frequency of waves was detected. The effect of L-NAME was prevented by the administration of L-Arginine. This study suggests an important role for the nitric oxide pathway in the distal propagation of the spontaneous motor activity of the alimentary tract.
Grossi
L
L
University G. D'Annunzio, School of Gastroenterology, Casa di Cura Pierangeli, Pescara, Italy.
Falcucci
M
M
Lapenna
D
D
Marzio
L
L
D000818:Animals; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007583:Jejunum / Q000187:drug effects / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology*; D011817:Rabbits; D013270:Stomach / Q000187:drug effects / Q000502:physiology
D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester