sildenafil-citrate and Acute-Lung-Injury

Inflammatory response and acute lung injury (ALI) occur in sodium taurocholate-induced severe acute pancreatitis (SAP). Because sildenafil has anti-inflammatory, anti-oxidant and immune-modulating effects, we investigated its effect on inflammatory and lung injury in sodium taurocholate-induced SAP-associated ALI rat lung.. Sodium taurocholate-induced SAP rats received sildenafil (100 mg/kg) or not and were compared to age-matched normal control animals. We evaluated inflammatory response by detecting the expression of inflammatory factors including IL-1β, IL-6 and TNF-α, and detected the level of lung injury through histopathological evaluation. Moreover, we also tested the protein expression of PCNA, P21, Bcl-2 and Bax in the lung.. Sildenafil administration rats had a low level of lung injury and inflammation. In addition, sildenafil significantly increased the expression of proliferation-related markers and decreased the expression of apoptosis-related markers in lung tissue.. Sildenafil administration may attenuate inflammation and lung injury by promoting proliferation and suppressing apoptosis in SAP rats.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Lung; Male; Pancreas; Pancreatitis; Rats, Sprague-Dawley; Sildenafil Citrate; Taurocholic Acid

Acute lung injury (ALI) is associated with deterioration of alveolar-capillary lining and transmigration and activation of inflammatory cells. Sildenafil, phosphodiesterase 5 (PDE5) inhibitor, inhibits degradation of cyclic guanosine monophosphate (cGMP) by competing with cGMP for binding site of PDE5. Positive effects of sildenafil treatment result from influencing proliferation of regulatory T cells and production of proinflammatory cytokines and autoantibodies as well as from modulation of platelet activation, angiogenesis, and pulmonary vasoreactivity. This study evaluated if intravenous sildenafil can influence inflammation, edema formation, apoptosis, and respiratory parameters in rabbits with a model of ALI induced by repetitive lung lavage by saline (30 ml/kg). animals were divided into 3 groups: ALI without therapy (ALI), ALI treated with sildenafil intravenously (1 mg/kg; ALI + Sil), and healthy ventilated controls (Control) which were oxygen-ventilated for 4 hours following treatment administration. during this period, respiratory parameters (ventilator pressures, lung compliance, blood gases, oxygenation indexes etc.) were regularly measured. at the end of experiment, animals were overdosed by anesthetics. The left lung was saline-lavaged and total and differential cell counts and protein content in the bronchoalveolar lavage fluid (BAL) were estimated. The right lung was used for determination of lung edema formation expressed as wet/dry lung weight ratio, for detection of inflammation and oxidative stress markers by ELISA methods, and for detection of lung epithelial cells apoptosis by TUNEL methods and level of caspase-3. Sildenafil treatment reduced leak of cells (P < 0.05), particularly of neutrophils (P < 0.001) into the lung, release of pro-inflammatory mediators (TNF-α, P < 0.001; IL-8 and IL-6, P < 0.01), level of nitrite/nitrate (P < 0.001), markers of oxidative damage (3-nitrotyrosine and malondialdehyde, both P < 0.01), lung edema formation (P < 0.01), protein content in BAL (P < 0.001), and apoptosis of epithelial cells (P < 0.01), and improved respiratory parameters. Concluding, the results indicate a future potential of PDE5 inhibitors also for the therapy of ALI.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Apoptosis; Bronchoalveolar Lavage; Cytokines; Disease Models, Animal; Epithelial Cells; Neutrophils; Nitrates; Nitrites; Phosphodiesterase 5 Inhibitors; Pulmonary Ventilation; Rabbits; Saline Solution; Sildenafil Citrate

Severe burn induces biochemical mediators such as reactive oxygen species that leads to lipid peroxidation which may have a key role in formation of acute lung injury (ALI). Sildenafil is a selective and potent inhibitor of cyclic guanosine monophosphate specific phosphodiesterase-5. Sildenafil preserves alveolar growth, angiogenesis, reduces inflammation and airway reactivity. The purpose of the present study was to evaluate the effects of different dosages of sildenafil in ALI due to severe scald burn in rats. Twenty-four rats were subjected to 30% total body surface area severe scald injury and were randomly divided into three equal groups as follow: control, 10 and 20mg/kg sildenafil groups. Levels of malondialdehyde (MDA), activities of glutathione peroxidase (Gpx), catalase (Cat), total oxidative stress (TOS), and total antioxidative capacity (TAC) were measured in both tissues and serums. Oxidative stress index (OSI) was calculated. A semi-quantitative scoring system was used for the evaluation of histopatological findings. Sildenafil increased Gpx, Cat, TAC and decreased MDA, TOS and OSI. Sildenafil decreased inflammation scores in lungs. Our results reveal that sildenafil is protective against scald burn related ALI by decreasing oxidative stress and inflammation and the dosage of 10mg/kg could be apparently better than 20mg/kg.

Topics: Acute Lung Injury; Animals; Biomarkers; Burns; Catalase; Disease Models, Animal; Female; Glutathione Peroxidase; Malondialdehyde; Oxidative Stress; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Rats; Rats, Wistar; Sildenafil Citrate; Sulfones