Pretreatment with adenosine and adenosine A1 receptor agonist protects against intestinal ischemia-reperfusion injury in rat

WOS: 000243916200008PubMed: 17278219AIM: To examine the effects of adenosine and A1 receptor activation on reperfusion-induced small intestinal injury. METHODS: Rats were randomized into groups with sham operation, ischemia and reperfusion, and systemic treatments with either adenosine or 2-chloro-N-6-cyclo- pentyladenosine, A1 receptor agonist or 8-cyclopentyl-1,3-dipropylxanthine, A1 receptor antagonist, plus adenosine before ischemia. Following reperfusion, contractions of ileum segments in response to KCl, carbachol and substance P were recorded. Tissue myeloperoxidase, malondialdehyde, and reduced glutathione levels were measured. RESULTS: Ischemia significantly decreased both contraction and reduced glutathione level which were ameliorated by adenosine and agonist administration. Treatment also decreased neutrophil infiltration and membrane lipid peroxidation. Beneficial effects of adenosine were abolished by pretreatment with A1 receptor antagonist. CONCLUSION: The data suggest that adenosine and A1 receptor stimulation attenuate ischemic intestinal injury via decreasing oxidative stress, lowering neutrophil infiltration, and increasing reduced glutathione content. (c) 2007 The WJG Press. All rights reserved

Neuroprotective Efficacy of the Peroxisome Proliferator-Activated Receptor-gamma Ligand in Chronic Cerebral Hypoperfusion

WOS: 000294411200002PubMed: 21675957Chronic cerebral hypoperfusion can cause learning and memory impairment and neuronal damage resembling the effects observed in vascular dementia. PPAR-gamma agonists were shown to modulate inflammatory response and neuronal death following cerebral ischemia. The present study was designed to evaluate possible neuroprotective effects of rosiglitazone, a PPAR-gamma agonist, in rat model of chronic cerebral hypoperfusion. Cerebral hypoperfusion was induced by permanent bilateral occlusion of the common carotid arteries. Oral administration of rosiglitazone (1.5, 3, and 6 mg/kg/day) or vehicle was carried out for 5 weeks, starting one week before the surgery. Cognitive performance was assessed using the Morris water maze. The density of S100B protein-immunoreactive astrocytes and the OX-42-labeled microglial activation were estimated. Synaptogenesis was also evaluated by the measurement of synaptophysin, the pre-synaptic vesicular protein, level via western blotting technique. Cerebral hypoperfusion for 30 days induced a significant cognitive impairment along with hyperactivation of both microglial and astroglial cells, and reduction of synaptophysin level. Rosiglitazone treatment (3 and 6 mg/kg) not only suppressed the activation of astrocytes and microglia markedly but also alleviated the impairment of memory and increased the synaptophysin level. In conclusion, our results suggest that the chronic administration of rosiglitazone significantly prevents chronic cerebral hypoperfusion-induced brain damage, at least, partly through suppressing glial activation and preserving synaptic plasticity. Thus, it appears that rosiglitazone may be a promising pharmacological agent in the development of therapeutic approaches for the prevention or treatment of cerebrovascular diseases.Turkish Scientific Research Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108S114, SBAG-HD-303]We have gratefully acknowledged the Research Projects Fund of Turkish Scientific Research Council (TUBITAK) for providing financial support that made the present study possible (the grant # 108S114, SBAG-HD-303)

Pretreatment with remifentanil protects against the reduced-intestinal contractility related to the ischemia and reperfusion injury in rat

BACKGROUND AND OBJECTIVES: Serious functional and structural alterations of gastrointestinal tract are observed in failure of blood supply, leading to gastrointestinal dismotility. Activation of opioid receptors provides cardioprotective effect against ischemia-reperfusion (I/R) injury. The aim of the present study was to determine whether or not remifentanil could reduce I/R injury of small intestine. METHODS: Male Wistar Albino rats were subjected to mesenteric ischemia (30 min) followed by reperfusion (3 h). Four groups were designed: sham control; remifentanil alone; I/R control; and remifentanil + I/R. Animals in remifentanil + I/R group were subjected to infusion of remifentanil (2 ug kg-1 min-1) for 60 min, half of which started before inducing ischemia. Collecting the ileum tissues, evaluation of damage was based on contractile responses to carbachol, levels of lipid peroxidation and neutrophil infiltration, and observation of histopathological features in intestinal tissue. RESULTS: Following reperfusion, a significant decrease in carbachol-induced contractile response, a remarkable increase in both lipid peroxidation and neutrophil infiltration, and a significant injury in mucosa were observed. An average contractile response of remifentanil + I/R group was significantly different from that of the I/R group. Lipid peroxidation and neutrophil infiltration were also significantly suppressed by the treatment. The tissue samples of the I/R group were grade 4 in histopathological evaluation. In remifentanil + I/R group, on the other hand, the mucosal damage was moderate, staging as grade 1. CONCLUSIONS: The pretreatment with remifentanil can attenuate the intestinal I/R injury at a remarkable degree possibly by lowering lipid peroxidation and leukocyte infiltration

Pretreatment with mineralocorticoid receptor blocker reduces intestinal injury induced by ischemia and reperfusion: involvement of inhibition of inflammatory response, oxidative stress, nuclear factor kappa B, and inducible nitric oxide synthase

WOS: 000341358100016PubMed: 24862878Background: Spironolactone (Sp), a mineralocorticoid receptor antagonist, protects against the ischemia reperfusion (IR) injury of retina, kidney, heart, and brain. We aimed to investigate the effects of Sp on intestinal IR injury. Methods: Male Wistar rats were randomly divided into: (1) a sham control group; (2) an IR control group, subjected to 30 min ischemia and 3 h reperfusion; (3) a group treated with Sp (20 mg/kg) for 3 d before the IR; and (4) a sham-operated control group treated with Sp (20 mg/kg). After the reperfusion, blood and intestinal tissue samples were collected to evaluate histopathologic state, neutrophil infiltration (by measuring myeloperoxidase activity), levels of the cytokines (tumor necrosis factor alpha, interleukin 1 alpha [IL-1 alpha], interferon gamma, monocyte chemotactic protein-1, granulocyte macrophage-colony stimulating factor, and IL-4), malondialdehyde (MDA) and reduced glutathione contents, and immunohistochemical expressions of nuclear factor kappa B, inducible nitric oxide synthase (iNOS), and caspase-3. Results: MDA content, myeloperoxidase activity, and plasma levels of tumor necrosis factor alpha, IL-1 alpha, and monocyte chemotactic protein-1 were all elevated in IR, indicating the oxidative stress and local and systemic inflammatory response. Sp administration markedly reduced the MDA content and the cytokine levels. The pretreatment alleviated intestinal injury, neutrophil infiltration, and the expressions of caspase-3, iNOS, and NF kappa B. Conclusions: The results implicate that Sp may have a strong protective effect against the intestinal IR injury. The effect can be mediated via suppression of both systemic inflammatory response and apoptosis through amelioration of oxidative stress and generation of proinflammatory cytokines, iNOS, caspase-3, and nuclear factor kappa B. Therefore, mineralocorticoid receptor antagonism might be of potential therapeutic benefit in cases of intestinal IR damage. (C) 2014 Elsevier Inc. All rights reserved

Comparison of the Effects of Bupivacaine, Lidocaine, and Tramadol Infiltration on Wound Healing in Rats

Hand l V, Hakimoglu S, Ozacmak H, Bektas S, Ozacmak HS, Ozdamar SO, Yurtlu S, Turan IO - Comparison of the Effects of Bupivacaine, Lidocaine, and Tramadol Infiltration on Wound Healing in Rats