Protective effects of trapidil in lung after abdominal aorta induced ischemia-reperfusion injury: an experimental study

'Bottom-hung window' trauma in cats: neurological evaluation and outcome in 71 cats with bilateral hindlimb injury

Objectives

Influence of neurological status on the mortality rate of paraparetic/paralysed cats presenting after entrapment in a bottom-hung window was evaluated. It was hypothesised that (1) loss of deep pain sensation at admission would not be a negative prognostic factor for regaining motor function and that (2) mortality rate would be influenced by the severity of neurological grade upon admission.

Methods

Clinical and pathological data of affected cats that presented at our institution between 2001 and 2012 for this specific trauma were collected retrospectively: breed, age, sex, last contact with owner (<3 hours and >3 hours), whether the cat was suffering from monoparesis or paraparesis/paraplegia, duration of hospitalisation, rectal temperature, surface temperature of the skin of the hindlimbs, femoral pulse and tone of the pelvic musculature. Neurological status was categorised according to Scott's classification scheme with neurological grade 1 representing spinal pain on manipulation down to neurological grade 5 representing paraplegia with no deep pain sensation.

Results

Data were collected for 98 cats that had been caught in the thoracolumbar area. A total of 71 cats were included in the statistical analysis after excluding 27 cats for the following reasons: monoparesis/monoplegia by getting one limb caught only (15), no initial neurological examination (5), was dead on arrival (1), caught within the thoracolumbar area but no clinical or neurological abnormalities (6). The proportional mortality rate overall was 35% (25/71) with 65% of these (16/25) dying with clinical signs of respiratory distress. The proportional mortality rate of patients with a neurological grade of 5 on admission was 55% (17/31).

Conclusions

Mortality was influenced by the severity of neurological grade on admission, with the majority of cats having a neurological grade of 5 (paraplegia with loss of deep pain perception) at admission dying (11/31) rather than undergoing euthanasia on admission at the owner's request (6/31). In the survivors' group, loss of deep pain perception was not a negative prognostic factor for regaining motor function although it was associated with mortality.

Lipid emulsion mitigates impaired pulmonary function induced by limb I/R in rats through attenuation of local cellular injury and the subsequent systemic inflammatory response/inflammation

Background

Limb ischemia/reperfusion causes inflammation and elicits oxidative stress that may lead to local tissue damage and remote organ such as lung injury. This study investigates pulmonary function after limb ischemia/reperfusion and the protective effect of a lipid emulsion (Intralipid).

Methods

Twenty-four rats were divided into three groups: sham operation group (group S), ischemia/reperfusion group (group IR), and lipid emulsion treatment group (group LE). limb ischemia/reperfusion was induced through occlusion of the infrarenal abdominal aorta for 3 h. The microvascular clamp was removed carefully and reperfusion was provided for 3 h.

Results

The mean arterial pressure in group LE was higher than group IR during the reperfusion period (P = 0.024). The heart rate of both group LE and IR are significantly higher than group S during the ischemia period(P < 0.001, P < 0.001, respectively). The arterial oxygen pressure of group LE was significantly higher than group IR (P = 0.003), the arterial carbon dioxide pressure of group LE were lower than that of group IR (P = 0.005). The concentration of plasma interleukin-6, tumor necrosis factor-α and malondialdehyde in group LE were significantly lower than group IR (P < 0.001, P = 0.009 and 0.029, respectively). The plasma superoxide dismutase activity in group LE was significantly higher than group IR (P = 0.029). The myeloperoxidase activity in lung tissues of group LE was significantly less than group IR (P = 0.046). Both muscle and lung in group IR were damaged seriously, whereas lipid emulsion (Intralipid) effectively reversed the damage. In summary, Intralipid administration resulted in several beneficial effects as compared to group IR, such as the pulmonary gas exchange and inflammatory.

Conclusions

The ischemic/reperfusion injury of limb muscles with resultant inflammatory damage to lung tissue can be mitigated by administration of a lipid emulsion (Intralipid, 20%, 5 ml/kg). The mechanisms attenuating such a physiological may be attributed to reduction of the degree of limb injury through a decrease in the release of local inflammatory mediators, a reduction of lipid peroxidation, and a blunting of the subsequent remote inflammatory response.

Melatonin attenuates lung injury in a hind limb ischemia-reperfusion rat model

OBJECTIVE

This study evaluated the protective antioxidant effect of melatonin on lung injury as a remote organ after skeletal muscle ischemia-reperfusion in rats.

METHODS

Thirty male Wistar rats were allocated randomly into three experimental groups: operated with no ischemia (Sham) group, ischemia-reperfusion group and ischemia-reperfusion+melatonin group. Hind limb ischemia was induced by clamping the femoral artery. After 2h ischemia, the clamp was removed and the animal underwent 24h reperfusion. Rats in the ischemia-reperfusion + melatonin group received melatonin (10 mg/kg i.v.), immediately before the clamp was removed. At the end of the trial, animals were euthanized and the lungs were removed for water content determination, histopathological and biochemical studies.

RESULTS

In the ischemia-reperfusion + melatonin group, tissues showed less intense histological abnormalities such as neutrophilic infiltration, intra-alveolar hemorrhage and edema compared with the ischemia-reperfusion group. Histopathologically, there was a significant difference (P < 0.05) between the two groups. The lung water content in the ischemia-reperfusion + melatonin group was significantly lower than the ischemia-reperfusion group (P < 0.05). Lung tissue myeloperoxidase (MPO) activity and nitric oxide (NO) level were significantly (P < 0.05) increased by ischemia-reperfusion. The increase in these parameters was reduced by melatonin. Comparing the ischemia-reperfusion+melatonin group with the sham group, no significant increase in all analyzed aspects of the research was observed.

CONCLUSIONS

These findings suggest that melatonin has preventive effects in lung tissue injury after transient femoral artery occlusion.

WITHDRAWN: Melatonin attenuates lung injury in a hind limb ischemia-reperfusion rat model

This article has been withdrawn for editorial reasons because the journal will be published only in English. In order to avoid duplicated records, this article can be found at http://dx.doi.org/10.1016/j.rppnen.2014.01.010. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Endothelin receptor antagonism by tezosentan attenuates lung injury induced by aortic ischemia-reperfusion

Tezosentan is a novel dual endothelin receptor antagonist. The purpose of this study was to examine the effect of tezosentan on lung injury induced by abdominal aortic ischemia-reperfusion (IR) in rats. Thirty-two Wistar-albino rats were randomized into four groups (eight per group) as follows: control group (sham laparotomy), aortic IR group (120 min ischemia and 120 min reperfusion), aortic IR + tezosentan group (a bolus intravenous injection of 10 mg/kg tezosentan before ischemia plus continuous intravenous infusion of 1 mg/kg/hr tezosentan during 120 min ischemia and 120 min reperfusion), and control + tezosentan. Blood and lung tissue samples were obtained for biochemical analysis. Protein concentrations in bronchoalveolar lavage fluid and lung wet/dry weight ratios were measured. A histological evaluation was also done. Aortic IR significantly increased (p < 0.05 vs. control group) and tezosentan significantly decreased (p < 0.05 vs. aortic IR group) the plasma level of tumor necrosis factor-alpha; lung tissue levels of malondialdehyde, catalase, and myleperoxidase; and protein concentration in bronchoalveolar lavage fluid and lung wet/dry weight ratio. Histological evaluation showed that tezosentan attenuated the morphological changes associated with lung injury. The results of this study indicate that tezosentan attenuates lung injury induced by aortic IR in rats. We propose that this protective effect of tezosentan is due to (1) reduced systemic inflammatory response, (2) reduced oxidative stress and lipid peroxidation in lung tissue, (3) reduced pulmonary microvascular leakage, and (4) inhibition of leukocyte infiltration into lung tissue.

The role of trapidil on neuronal apoptosis in neonatal rat model of hypoxic ischemic brain injury

BACKGROUND

Hypoxic ischemic brain injury (HIBI) is a common cause of neonatal mortality and morbidity. Trapidil is an antiplatelet agent and several studies demonstrate the beneficial effect of trapidil in various forms of tissue injury. The effects of trapidil on neuronal apoptosis in HIBI have not been reported previously.

AIMS

The aim of this study is to evaluate the effect of trapidil on neuronal apoptosis in neonatal rat model of HIBI.

STUDY DESIGN

Seven-day-old Wistar rat pups were subjected to right common carotid artery ligation and hypoxia (92% nitrogen and 8% oxygen) for 2h. They were treated with trapidil or saline either immediately before or after hypoxia. In sham group animals, neither ligation, nor hypoxia were performed. Neuronal apoptosis was evaluated by the terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) and caspase-3 staining methods.

RESULTS

Trapidil treatment either before or after hypoxia results in significant reduction of the numbers of apoptotic cells in both hemispheres, when it is compared with saline treatment group. The numbers of apoptotic cells in right hemispheres in all groups are significantly higher than that in the left hemispheres.

CONCLUSIONS

These results show that trapidil administration either before or after hypoxia reduces neuronal apoptosis and we propose that trapidil may be a novel approach for the therapy of HIBI.

The effect of Nomega-nitro-L-arginine methyl ester and L-arginine on lung injury induced by abdominal aortic occlusion-reperfusion

PURPOSE

The aim of this study was to examine the effects of Nomega-nitro-L-arginine methyl ester (L-NAME) and L-arginine on lung injury after aortic ischemia-reperfusion (IR).

METHODS

Twenty-four Wistar-Albino rats were randomized into four groups (n = 6) as follows: Control (sham laparotomy), Aortic IR (30 min ischemia and 120 min reperfusion), L-Arginine (intraperitoneal 100 mg kg(-1) live weight)+aortic IR, and L: -NAME (intraperitoneal 10 mg kg(-1) live weight)+aortic IR. In the lung specimens, the tissue levels of malondialdehyde (MDA), vascular endothelial growth factor (VEGF), and nitric oxide (NO) were measured and a histological examination was done.

RESULTS

Aortic IR increased MDA, VEGF, and NO. L-Arginine further significantly increased MDA and NO, and decreased VEGF (P < 0.05 vs aortic IR). L-NAME significantly decreased MDA and NO (P < 0.05 vs L-arginine+aortic IR) and increased VEGF (P < 0.05 vs other groups). A histological examination showed the aortic IR to significantly increase (P < 0.05 vs control) while L-arginine also further increased (P > 0.05 vs aortic IR), whereas L-NAME caused a significant decrease in pulmonary leukocyte infiltration (P < 0.05 vs aortic IR).

CONCLUSIONS

Our results indicate that L-arginine aggravates the lung injury induced by aortic IR, while L-NAME attenuates it.