[Mechanism of action of neurotensin on microcirculation, metabolism and motility of the small intestine].
The aim of this study was to investigate the influence of neurotensin on total microcirculatory blood flow, oxygen consumption, myoelectric activity and motility of the small bowel. The attempts were made to evaluate the role of L-Arginine, NO-system in the mechanism of action of this peptide on microcirculation, metabolism and motor-activity of the intestine. The experiments were performed in two experimental models--dogs and rats. In Vetbutal anesthetised animals the systemic arterial pressure, superior mesenteric artery blood flow, microcirculatory blood flow and myoelectric activity of the small bowel were continuously monitored. In experiments with dogs effective capillary index, arterio-venous oxygen difference and oxygen consumption were analysed. Neurotensin administered intraarterially caused a dose depended increase in total and microcirculatory blood flow in the small bowel in both groups of animals. The experiment with dogs showed the rise of effective capillary index and intestinal oxygen consumption. Administration of neurotensin changed the profile of myoelectric activity of the small bowel similar to that of postprandial hyperaemia. Inhibition of NO-synthase by the intravenous administration of L-NNA reduced significantly the amplitude of neurotensin hyperaemia. Pretreatment with L-Arginine, the substrate of NO-synthase reversed the hemodynamic, but not motility effects of neurotensin. The results presented proved the role of the L-Arginine-NO in circulatory mechanism, but not motility effects of neurotensin.
Sendur
R
R
Zakład Fizjologii Doświadczalnej Katedra Fizjologii Collegium Medicum UJ.
Thor
P
P
Biernat
J
J
Kozioł
R
R
Pawlik
W W
WW
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007269:Injections, Intra-Arterial; D007583:Jejunum / Q000098:blood supply / Q000187:drug effects / Q000502:physiology*; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D009496:Neurotensin / Q000378:metabolism* / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D009569:Nitric Oxide; D009496:Neurotensin; D001120:Arginine; D019001:Nitric Oxide Synthase