Melatonin pretreatment improves gastric mucosal blood flow and maintains intestinal barrier function during hemorrhagic shock in dogs.
Melatonin improves hepatic perfusion after hemorrhagic shock and may reduce stress-induced gastric lesions. This study was designed to investigate whether pretreatment with melatonin may influence gastric mucosal microcirculatory perfusion (μflow), oxygenation (μHbO2), or intestinal barrier function during physiological and hemorrhagic conditions in dogs.



In a randomized crossover study, five anesthetized foxhounds received melatonin 100 μg kg-1or vehicle (ethanol 5%) intravenously in the absence or presence of hemorrhagic shock (60 minutes, -20% blood volume). Systemic hemodynamic variables, gastric mucosal perfusion, and oxygenation were recorded continuously; intestinal barrier function was assessed intermittently via xylose absorption.



During hemorrhagic shock, melatonin significantly attenuated the decrease in μflow, compared with vehicle (-19±9 vs -43±10 aU, P<.05), without influence on μHbO2. A significant increase in xylose absorption was detected during hemorrhage in vehicle-treated dogs, compared with sham-operated animals (13±2 vs 8±1 relative amounts, P<.05); this was absent in melatonin-treated animals (6±1 relative amounts). Melatonin did not influence macrocirculation.



Melatonin improves regional blood flow suggesting improved oxygen delivery in gastric mucosa during hemorrhagic shock. This could provide a mechanism for the observed protection of intestinal barrier function in dogs.
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
Christian
0000-0002-2646-5629
C
Vollmer
Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
Andreas P M
APM
Weber
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
Martin
M
Wallenfang
Department of Hemostaseology, Düsseldorf University Hospital, Düsseldorf, Germany.
Till
T
Hoffmann
Plant Metabolism and Metabolomics Laboratory, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
Tabea
T
Mettler-Altmann
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
Richard
R
Truse
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
Inge
I
Bauer
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
Olaf
O
Picker
Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.|Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, Cologne, Germany.
Alexander M
AM
Mathes
D000818:Animals; D018592:Cross-Over Studies; D004285:Dogs; D005260:Female; D005753:Gastric Mucosa / Q000098:blood supply*; D007422:Intestines / Q000502:physiology; D008550:Melatonin / Q000008:administration & dosage* / Q000627:therapeutic use; D008833:Microcirculation / Q000187:drug effects; D010108:Oxyhemoglobins / Q000032:analysis; D011292:Premedication; D012039:Regional Blood Flow / Q000187:drug effects; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000503:physiopathology
D010108:Oxyhemoglobins; D008550:Melatonin
cardiac output; foxhounds; gastric perfusion; xylose absorption