Effects of gabexate mesilate (FOY) on ischemia-reperfusion-induced acute lung injury in dogs

Desflurane Preconditioning Protects Against Renal Ischemia-Reperfusion Injury and Inhibits Inflammation and Oxidative Stress in Rats Through Regulating the Nrf2-Keap1-ARE Signaling Pathway

OBJECTIVE

Kidney is sensitive to ischemia-reperfusion (I/R) injury because of its special structure and function. In this study, we aimed to explore the mechanism of desflurane (DFE) preconditioning effecting on renal I/R injury in rats.

METHODS

Renal I/R injury rats model was constructed, and the expressions of serum renal function parameters (blood urea nitrogen (BUN) and serum creatinine (SCr)) and lipid peroxidation-related factors were detected using corresponding commercial kits to assess the degrees of renal functional damage and oxidative stress. Hematoxylin--eosin (HE) staining and Masson trichrome staining were applied to measure the renal histologic damage. The expressions of inflammation-related factors were determined by ELISA assay. The cell apoptosis was analyzed using TUNEL, Western blot and immunohistochemistry (IHC). IHC was also used to detect the number of myeloperoxidase (MPO)-positive cells. The expressions of proteins associated with the Nrf2-Keap1-ARE pathway were assessed by Western blot and IHC.

RESULTS

DFE preconditioning inhibited I/R injury-induced BUN and SCr increase and renal histologic injury in rats. Also, DFE suppressed the inflammation, apoptosis and oxidative stress caused by renal I/R injury in vivo. In addition, DFE preconditioning repressed peroxide-related factors (MDA, MPO and NO) expressions and promoted antioxidant-related factors (GSH, SOD, GPx and CAT) expressions. In addition, DFE promoted Nrf2-Keap1-ARE-related proteins including Nrf2, NQO1, HO-1, γ-GCS, GSR and GCLc expressions.

CONCLUSION

DFE preconditioning protected the kidney as well as inhibited the inflammation, cell apoptosis and oxidative stress in renal I/R injury rats by activating the Nrf2-Keap1-ARE signaling pathway.

Lung Ischaemia-Reperfusion Injury: The Role of Reactive Oxygen Species

Lung ischaemia-reperfusion injury (LIRI) occurs in many lung diseases and during surgical procedures such as lung transplantation. The re-establishment of blood flow and oxygen delivery into the previously ischaemic lung exacerbates the ischaemic injury and leads to increased microvascular permeability and pulmonary vascular resistance as well as to vigorous activation of the immune response. These events initiate the irreversible damage of the lung with subsequent oedema formation that can result in systemic hypoxaemia and multi-organ failure. Alterations in the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been suggested as crucial mediators of such responses during ischaemia-reperfusion in the lung. Among numerous potential sources of ROS/RNS within cells, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, nitric oxide synthases and mitochondria have been investigated during LIRI. Against this background, we aim to review here the extensive literature about the ROS-mediated cellular signalling during LIRI, as well as the effectiveness of antioxidants as treatment option for LIRI.

Comparison of the efficacy of continuous i.v. infusion versus continuous regional arterial infusion of nafamostat mesylate for severe acute pancreatitis

Aim

Continuous regional arterial infusion (CRAI) of protease inhibitors may be effective in the treatment of severe acute pancreatitis (SAP), but it is more invasive than i.v. infusion. The purpose of this study was to examine the effectiveness of continuous i.v. infusion (CIVI) for SAP compared with CRAI by unifying the dose and the administration period of nafamostat mesylate.

Methods

This study comprised 32 patients with SAP who were divided into two groups: the CRAI group and the CIVI group. The protease inhibitor, nafamostat mesylate, was continuously infused at a rate of 200 mg/day for 5 days in both groups. Clinical outcomes including in-hospital mortality were examined.

Results

There were no significant between-group differences in in-hospital mortality and 90-day mortality. The duration from admission to treatment was significantly shorter in the CIVI group (median, 7 h vs. 2 h, P = 0.0001; CRAI group vs. CIVI group). The rate of mechanical ventilation was significantly less in the CIVI group than in the CRAI group (93% vs. 47%, P = 0.007). The CIVI group showed a tendency toward decreased length of intensive care unit stay (median, 13 days vs. 4 days, P = 0.085) and hospital stay (median, 19 days vs. 11 days, P = 0.072). Total costs during hospitalization were significantly lower in the CIVI group (median, $18,320 vs. $11,641, P = 0.049).

Conclusion

The effectiveness of CIVI with early nafamostat mesylate treatment after the development of SAP could be equivalent to, or better than, that of CRAI.

Acute respiratory distress syndrome induction by pulmonary ischemia-reperfusion injury in large animal models

Acute respiratory distress syndrome (ARDS) is a common critical pulmonary complication after esophagectomy and other thoracic surgeries (e.g., lung transplantation, pulmonary thromboendarterectomy). Direct pulmonary ischemia-reperfusion injury (PIRI) is known to play the main role in induction of ARDS in these cases. Large animal models are an appropriate choice for ARDS as well as PIRI study because of their physiological and anatomic similarities to the human body. With regard to large animal models, we reviewed different methods of inducing in situ direct PIRI and the commonly applied methods for diagnosing and monitoring ARDS or PIRI in an experimental research setting.

The effects of gabexate mesilate on the microsurgical reconstruction of the hepatic artery in living donor liver transplantation

OBJECTIVES

Microsurgical reconstruction of hepatic artery is essential but require challenging techniques especially for living donor liver transplantation (LDLT), because the recipient artery is short, located deep, and usable vessel grafts are limited. Furthermore, hepatic artery thrombosis (HAT) can be a lethal complication. Therefore, we began the systemic administration of gabexate mesilate, a strong serine protease inhibitor. It has often been effective to treat disseminated intravascular coagulation. The purpose of this study was to examine the effects of gabexate mesilate on the microvascular reconstruction.

METHODS

From 1991 to 2009, we performed 134 microsurgical reconstructions of LDLT. This retrospective investigation of those cases divided them into four groups: group I, anticoagulation with heparin (n = 3); group II, heparin and gabexate mesilate (20 mg/kg/d; n = 26); group III, heparin and full-dose gabexate mesilate (40 mg/kg/d; n = 72); and group IV, full-dose gabexate mesilate alone (n = 33). Groups I and II were mainly pediatric cases (left lobe grafts only); groups III and IV, adult cases (left: right = 57:48). Using ultrasonography to 14 days, we investigated HAT by examining pulsatile index, resistive index, and acceleration time.

RESULTS

HAT occurred in groups I, II, III, and IV at 33.3% (1/3), 11.5% (3/26), 6.9% (5/72), and 0% (0/33), respectively. The 5-year survival rates of groups III + IV versus groups I + II were 82.4% and 71.1%, respectively (P < .05). In HAT cases, even before the event the acceleration times were delayed to over 100 milliseconds.

CONCLUSION

Gabexate mesilate administration was safe for and protective of microvascular reconstructions in LDLT.

Effect of hypertonic saline pre-treatment on ischemia-reperfusion lung injury in pig

BACKGROUND

Hypertonic saline may be administered in the setting of lung transplantation but may affect the development of ischemia-reperfusion lung injury. This study investigated the effects of the pre-treatment by intravenous hypertonic saline in a pig model of single lung ischemia-reperfusion.

METHODS

Forty-three pigs (34 +/- 4 kg) under mechanical ventilation were randomly assigned to a left lung ischemia-reperfusion alone or preceded by 4-ml/kg 7.5% hypertonic saline, 33-ml/kg normal saline, or by the infusion of the vasodilator nicardipine. Animals without ischemia served as controls. After euthanasia, the left lung was sampled for histologic analysis and measurement of lung water and alveolar-capillary permeability.

RESULTS

Ischemia-reperfusion resulted in high-permeability pulmonary edema, hypoxemia, and increased interleukin-6 serum level. Hypertonic saline pre-treatment worsened pulmonary edema of the left lung (6.6 +/- 0.7 vs 4.8 +/- 0.8 ml/kg of body weight, p < 0.05) and resulted in a higher ratio of the protein level in the alveolar fluid to the serum protein level (0.41 +/- 0.04 vs 0.21 +/- 0.09, p < 0.05) and in a higher histologic damage score (11 [range, 9-11.75] vs 6.5 [range, 4.5-7.5], p < 0.05) without promoting pulmonary or systemic inflammation. Lung injury was affected neither by normal saline nor by nicardipine pre-treatment. Nicardipine did not influence the deleterious effect of hypertonic saline.

CONCLUSIONS

Pre-treatment by intravenous hypertonic saline worsened ischemia-reperfusion lung injury independently of its effects on the cardiac index or pulmonary circulation but probably through a direct effect of hyperosmolarity on endothelial permeability.

Effects of thermal preconditioning on the ischemia-reperfusion-induced acute lung injury in minipigs

Lung ischemia-reperfusion (I/R) injury plays an important role in many clinical issues. A series of mechanisms after I/R has been uncovered after numerous related studies. Organ preconditioning (PC) is a process whereby a brief antecedent event, such as transient ischemia, oxidative stress, temperature change, or drug administration, bestows on an organ an early or delayed tolerance to further insults by the same or different stressors. In this study, we want to uncover the optimal thermal PC patterns that cause maximal early or delayed protective effect on the subsequent pulmonary I/R with the use of miniature pig model. Twenty-eight 15- to 20-kg weight Lanyu miniature pigs are used and divided into four groups (seven sham operation control [NC], seven PC only [PC], seven I/R [I/R], and seven PC followed by I/R [PC + I/R]). The PC was performed with the animals being anesthetized and, using an alternative hyperthermic (40 degrees C) and normothermic moist air to ventilate their lungs for 15 min, respectively, for 2 cycles, followed by I/R, which consists of 90 min of blocking the perfusion and ventilation of the left lung followed by 240 min of reperfusion. Control animals had a thoracotomy with hilar dissection only. Indicators of lung injury included hemodynamic parameters, blood gas analysis, histopathological (lung pathology, wet/dry weight ratio, myeloperoxidase assay), and molecular biological profiles (interleukin-1beta [IL-1beta], IL-6, tumor necrosis factor-alpha by enzyme-linked immunosorbent assay analysis). Lung tissue heat shock protein 70 (HSP-70) expression was also detected by Western blotting. This model of lung I/R induced significant lung injury with pulmonary hypertension, increased pulmonary vascular resistance, and pulmonary venous hypoxemia at the ischemia side, increased pulmonary tissue injury score and neutrophil infiltration, increased wet/dry ratio, myeloperoxidase assay, tumor necrosis factor-alpha, IL-1beta, and IL-6 assay. This type of thermal PC would not injure the lung parenchyma or tracheal epithelium. Moreover, it could attenuate the I/R-related lung injury, with some of these parameters improved significantly. Increased expression of HSP-70 was also found in the group of PC plus I/R than the I/R only. Less prominent and transient increase in expression of HSP-70 was found in the PC group. We concluded that the intratracheal thermal PC can effectively attenuate I/R-induced lung injury through various mechanisms, including the decrease of various proinflammatory cytokines. The mechanism of its protective effect might be related to the increased expression of HSP-70.

Effects of gabexate mesilate on ischemia-reperfusion-induced testicular injury in rats

The aim of this study was to determine the effects of a synthetic serine protease inhibitor, gabexate mesilate (GM), in rats with ischemia-reperfusion (I-R) damage due to unilateral testicular torsion. Thirty male Sprague-Dawley rats were separated into three groups, each containing ten rats. A sham operation was performed in group 1 (control). In group 2 (I-R/untreated), 1 h detorsion of the testis was performed after 6 h of unilateral testicular torsion. In group 3 (I-R/GM), after performing the same surgical procedures as in group II, gabexate mesilate was given intravenously. In all experimental rats, ipsilateral orchiectomies were performed for histological examination and measuring the tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). MDA values and the testicular injury score decreased and SOD, CAT and GSH-Px values increased in the GM-treated group compared to the I-R/untreated group. The Tc-99m pertechnetate uptake ratio and the perfusion index were significantly decreased in the group 2 compared to the group 1 and 3 rats. In group 3, these values were significantly increased compared to group 2. Most of the specimens in the GM-treated group showed grade-I testicular injury. However, the injuries in the I-R/untreated rats varied between grade-III and grade-IV. The results of this study show that GM may play a role in reducing the injury caused by I-R.

Organ preconditioning: the past, current status, and related lung studies

Preconditioning (PC) has emerged as a powerful method for experimentally and clinically attenuating various types of organ injuries. In this paper related clinical and basic research issues on organ preconditioning issues were systemically reviewed. Since lung injuries, including ischemia-reperfusion and others, play important roles in many clinical results, including thromboembolism, trauma, thermal injury, hypovolemic and endotoxin shock, reimplantation response after organ transplantation, and many respiratory diseases in critical care. It is of interest to uncover methods, including the PCs, to protect the lung from the above injuries. However, related studies on pulmonary PC are relatively rare and still being developed, so we will review previous literature on experimental and clinical studies on pulmonary PC in the following paragraphs.

Pancreatic enzymes sustain systemic inflammation after an initial endotoxin challenge

BACKGROUND

Sepsis is accompanied by severe inflammation whose mechanism remains uncertain. We recently demonstrated that pancreatic proteases in the ischemic intestine have the ability to generate powerful inflammatory mediators that can be detected in the portal vein and in the general circulation. This study was designed to examine several circulatory and inflammatory indices during experimental endotoxemia and intraintestinal pancreatic protease inhibition.

METHODS

Immediately after intravenous endotoxin administration, the small intestine was subjected to intraluminal lavage with and without gabexate mesilate, an inhibitor of pancreatic proteases. Shams and rats without lavage served as controls. Hemodynamics, leukocyte (neutrophil and monocyte), and endothelial cell activation, as well as organ injury in the intestine and the cremaster muscle, were examined.

RESULTS

After endotoxin administration, control rats developed hypotension, tachycardia, hyperventilation, and leukopenia. The intestine and plasma contained mediators that activated leukocytes. The leukocyte-endothelial interaction within the cremaster muscle microcirculation was enhanced. Endotoxin administration resulted in elevated interleukin-6 plasma levels. Histologic evidence indicated liver and intestinal injury. In contrast, blockade of pancreatic proteases in the intestinal lumen significantly improved hemodynamic parameters and reduced all indices of inflammation in plasma and cell injury in skeletal muscle microcirculation.

CONCLUSIONS

Inflammatory mediators derived from the intestine by pancreatic proteases may be involved in the prolonged inflammatory response and sustain symptoms of sepsis after endotoxin challenge.

Protective effects of inhaled nitric oxide and gabexate mesilate in lung reperfusion injury after transplantation from non-heart-beat donors

BACKGROUND

The use of lung grafts from non-heart-beat donors (NHBDs) is one way of solving the critical donor organ shortage. Inhaled nitric oxide (NO) and gabexate mesilate (FOY), a protease inhibitor, can attenuate some types of neutrophil-mediated tissue injury. Using an isolated lung ventilation and perfusion model, we studied the effects of these agents on reperfusion injury following lung transplantation from NHBDs.

METHODS

Five groups of minipigs were studied. In group 1(n = 6), the lungs were flushed and harvested after cardiac arrest, and were reperfused for 2 hours after 2 hours of cold ischemia. In group 2 (n = 6), the lungs were harvested after 2 hours of in situ warm ischemia, followed by 2 hours of cold ischemia and 2 hours of reperfusion. In groups 3 (n = 7), 4 (n = 7), and 5 (n = 6), the procedure was the same as in group 2, except in group 3, NO was inhaled before and after ischemia, in group 4, FOY was given intravenously, and in group 5, a combination of inhaled NO and intravenous FOY were administered.

RESULTS

Compared with group 1, group 2 had higher mean pulmonary arterial pressure, vascular resistance, and lower arterial blood oxygen tension. Furthermore, these negative effects of warm ischemia were also reflected in the contents of bronchoalveolar lavage fluid, tissue myeloperoxidase (MPO) activity, histology, and permeability change. Either FOY or NO administration (groups 3 or 4) ameliorated the associated injury. A combination of FOY and NO use (group5) decreased the parameters of lung reperfusion injury measurement to a larger degree than either agent individually.

CONCLUSIONS

The inhaled NO and FOY can protect NHBD lung grafts at an early reperfusion period. Their use in combination has an additive protective effect that might be applied to the protection of NHBD grafts from preservation and reperfusion injury.