alpha-naphthyl-thiourea and Disease-Models--Animal

Acute lung injury (ALI) is a syndrome of inflammation and increased permeability of the blood-gas barrier. It is associated with high morbidity and mortality. Despite intensive research, treatments remain limited. The aim of the present study was to investigate the protective efficacy of a specific peripheral benzodiazepine receptor ligand, Ro5-4864, in experimental models of ALI in rats.. ALI was generated by four different methods: (1) intravenous (tail vein) injection of Escherichia coli (0111:B4) lipopolysaccaride (LPS), (2) cecal ligation and puncture (CLP), (3) mesenteric ischemia/reperfusion, and (4) intraperitoneal injection of α-naphthylthiourea (ANTU). Ro5-4864 was administered to rats intraperitoneally 30 min before ANTU and LPS administration or intravenously 15 min before reperfusion and CLP. The levels of pulmonary edema (lung weight/body weight ratio) and pleural effusion were measured, and the severity of ALI was scored (0-3).. Ro5-4864 showed a dose-dependent and significant prophylactic effect on the ANTU-induced lung weight/body weight and pleural effusion/body weight ratios and histopathologic scores. Ro5-4864 also showed significant prophylactic effects against the LPS-induced lung weight/body weight ratio and histopathologic scores. Ro5-4864 significantly decreased the intra-alveolar edema and perialveolar hemorrhage scores in the CLP group. However, we found no prophylactic effect of Ro5-4864 on mesenteric ischemia/reperfusion-induced ALI at the dose used (2 mg/kg intraperitoneally).. These results have demonstrated, for the first time, a protective effect of Ro5-4864 on experimental ALI induced by ANTU, LPS, and CLP. Ro5-4864 might be a useful therapeutic agent for lung diseases, including ALI, in intensive care patients.

Topics: Acute Lung Injury; Animals; Benzodiazepinones; Disease Models, Animal; GABA-A Receptor Agonists; Lipopolysaccharides; Lung; Male; Rats; Rats, Wistar; Receptors, GABA-A; Survival Rate; Thiourea

Acute lung injury is an inflammatory syndrome that increases the permeability of the blood-gas barrier, resulting in high morbidity and mortality. Despite intensive research, treatment options remain limited. We investigated the protective efficacy of tezosentan, a novel, dual endothelin receptor antagonist, in an experimental model of alpha-naphthylthiourea (ANTU)-induced acute lung injury in rats. ANTU was intraperitoneally (i.p.) injected into rats at a dose of 10 mg/kg. Tezosentan was injected 30 minutes before ANTU was subcutaneously (s.c.) injected at doses of 2, 10, or 30 mg/kg, 60 minutes before ANTU was injected at doses of 2, 10, or 30 mg/kg (i.p.), and 90 minutes before ANTU at a dose of 10 mg/kg (i.p.). Four hours later, the lung weight/body weight (LW/BW) ratio and pleural effusion (PE) were measured. When injected 30 minutes before ANTU at doses of 2, 10, or 30 mg/kg (s.c.), tezosentan had no effect on lung pathology. When injected 60 minutes before ANTU at doses of 2, 10, or 30 mg/kg (i.p.) or 90 minutes before ANTU (10 mg/kg, i.p.), tezosentan significantly decreased the PE/BW ratio and had a prophylactic effect on PE formation at all doses. Therefore, tezosentan may attenuate lung injury. Furthermore, its acute and inhibitory effects on fluid accumulation were more effective in the pleural cavity than in the interstitial compartment in this experimental model.

Topics: Acute Lung Injury; Animals; Disease Models, Animal; Endothelin Receptor Antagonists; Lung; Male; Pyridines; Rats; Rats, Wistar; Tetrazoles; Thiourea

We assessed the effects of dexmedetomidine in a rat model of α-naphthylthiourea (ANTU)-induced acute lung injury.. Forty Wistar Albino male rats weighing 200-240 g were divided into 5 groups (n = 8 each), including a control group. Thus, there were one ANTU group and three dexmedetomidine groups (10-, 50-, and 100-μg/kg treatment groups), plus a control group. The control group provided the normal base values. The rats in the ANTU group were given 10 mg/kg of ANTU intraperitoneally and the three treatment groups received 10, 50, or 100 μg/kg of dexmedetomidine intraperitoneally 30 min before ANTU application. The rat body weight (BW), pleural effusion (PE), and lung weight (LW) of each group were measured 4 h after ANTU administration. The histopathologic changes were evaluated using hematoxylin-eosin staining.. The mean PE, LW, LW/BW, and PE/BW measurements in the ANTU group were significantly greater than in the control groups and all dexmedetomidine treatment groups (P < 0.05). There were also significant decreases in the mean PE, LW, LW/BW and PE/BW values in the dexmedetomidine 50-μg/kg group compared with those in the ANTU group (P < 0.01). The inflammation, hemorrhage, and edema scores in the ANTU group were significantly greater than those in the control or dexmedetomidine 50-μg/kg group (P < 0.01).. Dexmedetomidine treatment has demonstrated a potential benefit by preventing ANTU-induced acute lung injury in an experimental rat model. Dexmedetomidine could have a potential protective effect on acute lung injury in intensive care patients.

Topics: Acute Lung Injury; Adrenergic alpha-2 Receptor Agonists; Animals; Dexmedetomidine; Disease Models, Animal; Drug Interactions; Lung; Male; Pleural Effusion; Pneumonia; Pulmonary Edema; Rats; Rats, Wistar; Rodenticides; Thiourea

The hypothesis that the changes in the respiratory system pressure- volume (PV) curve during pulmonary edema mainly reflect distal airway obstruction was investigated in rats. Normal rats had a well-defined upper inflection point (UIP) at low airway pressure. Airway occlusion by liquid instillation decreased compliance (Crs) and the volume (Vuip) of the UIP, and increased end-inspiratory pressure. The same changes were observed during the progression of edema produced by high volume ventilation (HV). Changes in Vuip and in Crs produced by HV were correlated with edema severity in normal rats or rats with lungs preinjured with alpha-naphthylthiourea. Vuip and Crs changes were proportional, reflecting compression of the PV curve on the volume axis and suggesting reduction of the amount of ventilatable lung at low airway pressure. In keeping with this explanation, the lower Vuip and Crs were before HV, the more severe HV-induced edema was in alpha-naphthylthiourea-injected rats. When edema was profuse, PV curves displayed a marked lower inflection point (LIP), the UIP at low pressure disappeared but another was seen at high volume above the LIP, and the correlation between Vuip changes and edema severity was lost. These observations may have clinical relevance in the context of the "open lung" strategy.. ventilator-induced lung injury; respiratory mechanics; acute respiratory distress syndrome

Topics: Airway Resistance; Animals; Disease Models, Animal; Inspiratory Capacity; Lung Compliance; Lung Volume Measurements; Male; Predictive Value of Tests; Pulmonary Edema; Rats; Rats, Wistar; Regression Analysis; Respiration, Artificial; Respiratory Distress Syndrome; Severity of Illness Index; Thiourea

Pleural fluid (PF) proteins either derive from serum by diffusion or are locally secreted within the pleural space. Another hypothetical origin is a leakage of lung secretory proteins across the visceral pleura. To test this hypothesis, we investigated the occurrence, sources, and determinants in PF of CC16, a small-size and readily diffusible protein of 16 kDa secreted by bronchiolar Clara cells. CC16 concentration was determined by a sensitive latex immunoassay in serum and PF of 117 subjects (86 exudates and 31 transudates) and, for purpose of comparison, in ascites samples from another group of 38 subjects (7 exudates and 31 transudates). CC16 was also studied in serum and PF of normal rats and in rats with pleural exudate induced by alpha-naphthyl-thiourea (ANTU). The levels of CC16 in PF and ascites were highly correlated with that in serum, suggesting a diffusional exchange across the pleural/blood and peritoneal/blood barriers. Whereas CC16 occurs at similar levels in ascites and serum, the protein was found to be more concentrated in PF than in serum in both humans (geometric mean in microg/L, 26.2 versus 14.6, p < 0.0001) and rats (213 versus 16.2, p < 0.001). A local synthesis of CC16 appeared unlikely in view of the lack of CC16-immunostaining in pleura of both species. The only plausible explanation for these findings is that CC16 in PF originates from two sources: diffusion from plasma and a leakage from the lung into the pleural space across the semipermeable visceral pleura. This interpretation is supported by a markedly increased leakage of CC16 in experimental exudates induced by ANTU and the finding of high CC16 concentrations in human transudates associated with congestive heart failure, two conditions wherein PF has been shown to arise from the interstitial spaces of the lung.

Topics: Aged; Animals; Ascites; Biomarkers; Blood Proteins; Bronchi; Creatinine; Diffusion; Disease Models, Animal; Enzyme Inhibitors; Exudates and Transudates; Female; Heart Failure; Humans; Lung; Male; Middle Aged; Peritoneum; Phospholipases A; Pleura; Pleural Effusion; Proteins; Rats; Rats, Sprague-Dawley; Smoking; Thiourea; Uteroglobin

Lungs were damaged with alpha-naphthylthiourea (ANTU) and various compounds were used to block its effect. Although the results are variable, superoxide dismutase, catalase and dimethylsulfoxide all protected against ANTU, indicating that OH radicals are responsible for this type of lung injury. Leukocytes do not appear to be required for the damage to occur; however, hydroxurea (given over 2 days) did block the ANTU damage when neutrophils were decreased to 1/2 normal values or when administered acutely. The free radicals may be generated by the cyclooxygenase pathway since ibuprofen blocked the ANTU damage, whereas blocking xanthine oxidase using allopurinol failed to prevent the lung damage.

Topics: Animals; Blood Pressure; Capillary Permeability; Dimethyl Sulfoxide; Disease Models, Animal; Dogs; Endothelium; Free Radicals; Lung; Oxygen; Pulmonary Circulation; Superoxide Dismutase; Thiourea

The effect of pulmonary oedema on the pharmacokinetic function of rat lungs was studied using prostaglandin E2 (PGE2) as substrate; oedema was induced by alpha-naphthyl thiourea (ANTU). Male rats were given a single i.p. injection of ANTU (10 mg/kg). Lung wet weight, dry:wet weight ratio and pleural transudate were measured at fixed times up to 50 hr after treatment. Wet weight was increased after 4 hr and remained higher than controls until 50 hr; dry:wet weight ratios were different only at 6 and 16 hr. Survival of PGE2 (measured by bioassay) was increased at 4 hr, reached a peak value of about six times the control survival at 6 hr and returned to normal by 50 hr. Using 14C-PGE2 as substrate, survival was maximal at 16 hr and back to normal by 50 hr. The efflux profiles of radioactivity showed an increase in T1/2 by 4 hr rising to a maximum at 28 hr and a normal value at 50 hr. Changes in PGE2 survival precede the period of oedema (assessed by dry:wet ratio) and could be used as an early warning of oedematous states. This altered pharmacokinetic function of lung could also have systemic effects.

Topics: Animals; Dinoprostone; Disease Models, Animal; Exudates and Transudates; Inactivation, Metabolic; Kinetics; Lung; Male; Organ Size; Prostaglandins E; Pulmonary Edema; Rats; Rats, Inbred Strains; Thiourea