ABSTRACT
Title
Pharmacological modulation of 5HT1A receptors in mice mesenteric ischemia/reperfusion injury: protective effect of Buspirone and WAY100135.
Authors
V. Arcaro1, F. Saccani1, G. Vegezzi1, A. Rapalli1, V. Ballabeni1, S. Bertoni1, E. Barocelli1
1Dept. of Pharmacological, Biological and Applied Chemical Sciences, University of Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy.
1Dept. of Pharmacological, Biological and Applied Chemical Sciences, University of Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy.
Abstract
Background and Aim. Mesenteric ischemia-reperfusion (I/R) is a dangerous condition that can occur as a consequence of vascular surgery or transplantation and can lead to microvascular alterations and pro-inflammatory mediators production.
Serotonin (5HT) is involved in many pathophysiological processes in the gut. Indeed it modulates intestinal motility, vascular tone and secretion through the interaction with multiple receptor subtypes and it is released during inflammatory responses as well.
Aim of our study was to investigate the involvement of the presynaptic receptor 5HT1A in the local inflammatory response provoked by mesenteric I/R.
Materials and Methods. Accordingly the effects of different 5HT1A receptor ligands such as Buspirone (partial agonist), 8-OH-DPAT (agonist) and WAY100135 (antagonist) were assessed in mice subjected to mesenteric I/R.
Intestinal ischemia was induced in female Swiss mice by occlusion of the superior mesenteric artery (45min) followed by 5h reperfusion (I/R). Sham Operated (SO) mice served as controls. Buspirone (10mg/kg), 8-OH-DPAT (1mg/kg), WAY100135 (5mg/kg) or saline were intravenously administrated 5min before ischemia.
All experiments were performed according to Guiding Principles in the Care and Use of Animals (DL116/92).
Results.Intestinal I/R significantly increased myeloperoxidase activity,index of leukocyte infiltration, (22.55±3.62 vs 0.28±0.39mU/mg; P<0.001) in jejunum, and malondialdehyde levels, index of lipoperoxidation, (52.08± 7.70 vs 16.70±1.80mmol/g; P<0.001) in ileum. Edema was produced (wet to dry weight ratio) (jejunum: 3.84±0.15 vs 2.56±0.09; P<0.001; ileum: 4.26±0.20 vs 2.39±0.09; P<0.001) and Heme-oxygenase-1 levels (HO-1) , index of oxidative stress, were increased (550.86±95.93 vs 322.40±24.23 ng/ml plasma; P<0.05) in I/R mice compared to SO saline treated mice.
Buspirone and WAY100135 significantly reduced MDA levels (respectively 28.74±6.29; P<0.01 and 19.94±2.50; P<0.001) and improved vascular permeability in jejunum and ileum (3.28±0.18 and 3.56±0.24, P<0.05; 3.46±0.13 and 3.68±0.15; P<0.05), Buspirone also markedly reduced neutrophil recruitment (8.97±2.85; P<0.01). Moreover Buspirone and WAY100135 prevented the increase of plasmatic HO-1 levels induced by I/R (respectively 395.105±55.87 and 380.66±41.45 vs 550.86±95.93). None of the inflammatory parameters was significantly modified by 8-OH-DPAT treatment.
Conclusions.These results prove that Buspirone and WAY100135 exert a protective role against mesenteric I/R alterations in mice, due to their antagonist effect on 5HT1A receptors.
Serotonin (5HT) is involved in many pathophysiological processes in the gut. Indeed it modulates intestinal motility, vascular tone and secretion through the interaction with multiple receptor subtypes and it is released during inflammatory responses as well.
Aim of our study was to investigate the involvement of the presynaptic receptor 5HT1A in the local inflammatory response provoked by mesenteric I/R.
Materials and Methods. Accordingly the effects of different 5HT1A receptor ligands such as Buspirone (partial agonist), 8-OH-DPAT (agonist) and WAY100135 (antagonist) were assessed in mice subjected to mesenteric I/R.
Intestinal ischemia was induced in female Swiss mice by occlusion of the superior mesenteric artery (45min) followed by 5h reperfusion (I/R). Sham Operated (SO) mice served as controls. Buspirone (10mg/kg), 8-OH-DPAT (1mg/kg), WAY100135 (5mg/kg) or saline were intravenously administrated 5min before ischemia.
All experiments were performed according to Guiding Principles in the Care and Use of Animals (DL116/92).
Results.Intestinal I/R significantly increased myeloperoxidase activity,index of leukocyte infiltration, (22.55±3.62 vs 0.28±0.39mU/mg; P<0.001) in jejunum, and malondialdehyde levels, index of lipoperoxidation, (52.08± 7.70 vs 16.70±1.80mmol/g; P<0.001) in ileum. Edema was produced (wet to dry weight ratio) (jejunum: 3.84±0.15 vs 2.56±0.09; P<0.001; ileum: 4.26±0.20 vs 2.39±0.09; P<0.001) and Heme-oxygenase-1 levels (HO-1) , index of oxidative stress, were increased (550.86±95.93 vs 322.40±24.23 ng/ml plasma; P<0.05) in I/R mice compared to SO saline treated mice.
Buspirone and WAY100135 significantly reduced MDA levels (respectively 28.74±6.29; P<0.01 and 19.94±2.50; P<0.001) and improved vascular permeability in jejunum and ileum (3.28±0.18 and 3.56±0.24, P<0.05; 3.46±0.13 and 3.68±0.15; P<0.05), Buspirone also markedly reduced neutrophil recruitment (8.97±2.85; P<0.01). Moreover Buspirone and WAY100135 prevented the increase of plasmatic HO-1 levels induced by I/R (respectively 395.105±55.87 and 380.66±41.45 vs 550.86±95.93). None of the inflammatory parameters was significantly modified by 8-OH-DPAT treatment.
Conclusions.These results prove that Buspirone and WAY100135 exert a protective role against mesenteric I/R alterations in mice, due to their antagonist effect on 5HT1A receptors.