Lactate Dehydrogenase Activity In Bronchoalveolar Lavage Fluid Research Articles

Protective effect of NMDA receptor antagonist memantine on acute lung injury in mice

To investigate the protective effect of a non-specific NMDA receptor antagonist memantine on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Healthy male mice were divided into 4 groups: a normal group, a memantine group, an ALI group and a memantine+ALI group. The ALI group was induced by intraperitoneal injection of LPS (10 mg/kg). Memantine (10 mg/kg) was injected intraperitoneally before the injection of LPS to determine the effect of blockade of NMDA receptor in the memantine+ALI group. The lung wet/dry ratio was detected. HE staining was preformed to show the morphological changes in the lung tissue. Myeloperoxidase enzyme (MPO) activity and malondialdehyde (MDA) content in the lung tissue were detected. ELISA was used to detect the tumor necrosis factor-α (TNF-α) content and lactate dehydrogenase (LDH) activity in the bronchoalveolar lavage fluid (BALF). Memantine pretreatment improved the LPS-induced ALI lung tissue morphological changes, reduced their lung wet/dry ratio, the levels of TNF-α and LDH activity in BALF, and also reduced the MPO and MDA content in the lung tissue. Blockade of NMDA receptors can ameliorate LPS-induced mice ALI.

Effects of copper nanoparticle exposure on host defense in a murine pulmonary infection model

BackgroundHuman exposure to nanoparticles (NPs) and environmental bacteria can occur simultaneously. NPs induce inflammatory responses and oxidative stress but may also have immune-suppressive effects, impairing macrophage function and altering epithelial barrier functions. The purpose of this study was to assess the potential pulmonary effects of inhalation and instillation exposure to copper (Cu) NPs using a model of lung inflammation and host defense.MethodsWe used Klebsiella pneumoniae (K.p.) in a murine lung infection model to determine if pulmonary bacterial clearance is enhanced or impaired by Cu NP exposure. Two different exposure modes were tested: sub-acute inhalation (4 hr/day, 5 d/week for 2 weeks, 3.5 mg/m3) and intratracheal instillation (24 hr post-exposure, 3, 35, and 100 μg/mouse). Pulmonary responses were evaluated by lung histopathology plus measurement of differential cell counts, total protein, lactate dehydrogenase (LDH) activity, and inflammatory cytokines in bronchoalveolar lavage (BAL) fluid.ResultsCu NP exposure induced inflammatory responses with increased recruitment of total cells and neutrophils to the lungs as well as increased total protein and LDH activity in BAL fluid. Both inhalation and instillation exposure to Cu NPs significantly decreased the pulmonary clearance of K.p.-exposed mice measured 24 hr after bacterial infection following Cu NP exposure versus sham-exposed mice also challenged with K.p (1.4 × 105 bacteria/mouse).ConclusionsCu NP exposure impaired host defense against bacterial lung infections and induced a dose-dependent decrease in bacterial clearance in which even our lowest dose demonstrated significantly lower clearance than observed in sham-exposed mice. Thus, exposure to Cu NPs may increase the risk of pulmonary infection.

Absorption and safety of alendronate, a nitrogen-containing bisphosphonate, after intrapulmonary administration in rats

Alendronate, a nitrogen-containing bisphosphonate, has been used as a first-choice drug for the treatment of hypercalcemia and osteoporosis. In the present study, we examined the absorption and safety of alendronate after intrapulmonary administration in rats. The bioavailability (BA) of alendronate after intrapulmonary administration was 47% at a dose of 5 mg/kg, while the BA after oral administration was only 2.9% at a dose of 50 mg/kg in rats. Plasma calcium level, an index of the pharmacological effect of alendronate, was effectively reduced after intrapulmonary administration of alendronate. Furthermore, alendronate continuously reduced the increase in plasma calcium levels for 9 days after a single intrapulmonary administration in rats with 1α-hydroxyvitamin-D 3-induced hypercalcemia. Intrapulmonary administration of alendronate also effectively suppressed the decrease in bone mass in a rat model of osteoporosis. Alendronate significantly increased the activity of lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF), indicating that pulmonary mucosal damage was induced by intrapulmonary administration of alendronate. However, co-administration of superoxide dismutase (SOD) with alendronate completely suppressed the alendronate-induced increase in LDH activity in BALF, while maintaining sufficient pulmonary absorption and therapeutic effects of alendronate in rats with 1α-hydroxyvitamin-D 3-induced hypercalcemia. These findings indicated that the lung is a promising, noninvasive alternative route for the delivery of alendronate in the treatment of bone diseases.

Pulmonary toxicity of thuringiensin administered intratracheally in Sprague–Dawley rats

The purpose of this work is to evaluate the pulmonary toxicity of purified thuringiensin in Sprague–Dawley rats. Rats were intratracheally instillated with 0, 0.4, 0.8, 1.6, 3.2, 6.4 and 9.6 mg/kg body weight of thuringiensin. The results indicated that the acute pulmonary LD 50 of thuringiensin for rats was 4.4 mg/kg. The total number of inflammatory cells and lactate dehydrogenase (LDH) activity in the bronchoalveolar lavage (BAL) fluid increased in a dose-dependent manner after thuringiensin instillation. Furthermore, an effective dose of 1.6 mg/kg was selected for the time course study of pulmonary toxicity. The treated animals showed a significant increase in the weights of the lungs, hydroxyproline levels in the lungs and total number of cells in BAL fluid 2, 4, 7, 14, 28 and 56 days after treatment. In comparison with the control, the total protein concentrations in BAL fluid were increased by 361, 615, 116, 41, 34 and 41%, after 2, 4, 7, 14, 28 and 56 days, respectively. The LDH activity in BAL fluid showed a significant increase after 1, 2, 4, 7, 14, 28 and 56 days. The increases in fibronectin levels were 164, 552, 490, 769, 335, 257 and 61% at the corresponding times, but neither tumor necrosis factor nor interleukin-1 increased. The treated rats presented abnormal histology including distributed inflammation in the bronchioles and alveoli, bronchial cellular necrosis on days 1 and 2, and areas of septal thickening with cellular infiltration and collagen deposit in the intestinal and alveolar spaces on days 4–56. Based on these biochemical and pathological parameters, intratracheal instillation of purified thuringiensin might cause significant pulmonary toxicity in rats.

Comparative Toxicity of Standard Nickel and Ultrafine Nickel in Lung after Intratracheal Instillation

A comparison was made of the bronchoalveolar lavage fluid (BALF) response to ultrafine nickel (Uf-Ni) and standard-sized nickel (Std-Ni). Rats were intratracheally instilled with 0, 0.1, 0.5, 1 and 5 mg Uf-Ni and Std-Ni, respectively. At 3 d after instillation, the body weight and wet lung weight were determined. At the same time, BALF was analyzed for lactate dehydrogenase (LDH), total protein (TP), tumor necrosis factor-alpha (TNF-alpha), and total cell and differential cell counts. The results showed that indicators of lung injury and inflammation in BALF were markedly raised with increased Uf-Ni and Std-Ni for each from 0 to 1 mg, and there were no differences in the indices between instillation of Uf-Ni at 1 mg and 5 mg. The results also showed that the effects of Uf-Ni on the indices were significantly higher than those of Std-Ni. Additional groups of rats were intratracheally instilled with 1 mg of Uf-Ni or Std-Ni, and wet lung weight and BALF profiles were analyzed at 1, 3, 7, 15 and 30 d later. The effect of Uf-Ni and Std-Ni on indices that can be presumed to reflect epithelial injury and permeability (LDH or TP), and release of proinflammatory cytokine (TNF-alpha) were increased throughout the 30 d post-exposure and the effects of Uf-Ni on these indices were significantly higher than those of Std-Ni from 1 to 30 d after instillation. Moreover, the number of neutrophils and LDH activity in BALF of rats after exposure to Uf-Ni were significantly greater than those of Std-Ni-exposed rats up to 30 d after instillation. Our findings suggest that Uf-Ni has a much more toxic effect on the lung than St-Ni, but the mechanism remains to be elucidated.

4-Vinylphenol-induced pneumotoxicity and hepatotoxicity in mice.

4-Vinylphenol (4-hydroxystyrene, 4-ethenylphenol, 4-VP) occurs naturally in some foods and has been used as a flavoring agent in food products. It is used synthetically in the production of polymers and resins. It has also been reported to be a minor metabolite of styrene in rats and humans. Varying doses of 4-vinylphenol were administered ip to mice. Hepatotoxicity was assessed by measuring serum sorbitol dehydrogenase (SDH) and by light microscopy. Pneumotoxicity was assessed by measuring proteins, cells, and lactate dehydrogenase activity in bronchoalveolar lavage fluid (BALF) and by light microscopy. 4-VP caused a dose-dependent increase in serum SDH and mild hepatocellular swelling. It caused an increase in cell number and lactate dehydrogenase activity in BALF. Microscopically, there was widespread and severe necrosis of the bronchioles by 12 hours. Re-epithelialzation of the bronchioles was evident by 48 hours. These studies indicate that 4-vinylphenol is both hepatotoxic and pneumotoxic.

Comparison of low doses of aged and freshly fractured silica on pulmonary inflammation and damage in the rat

Most previous studies of silica toxicity have used relatively high exposure doses of silica. In this study, male rats received by intratracheal instillation either vehicle, aged or freshly fractured silica at a dose of either 5 μg/rat once a week for 12 weeks (total dose=60 μg) or 20 μg/rat once a week for 12 weeks (total dose=240 μg). One week after the last exposure, bronchoalveolar lavage (BAL) was conducted and markers of pulmonary inflammation, alveolar macrophage (AM) activation and pulmonary damage were examined. For rats exposed to a total of 60 μg silica, both aged and freshly fractured silica increased polymorphonuclear leukocytes (PMN) yield and AM activation above control to a similar degree, but no evidence of pulmonary damage, as measured by BAL fluid lactate dehydrogenase activity or albumin concentration, was detected. For rats exposed to 240 μg silica, aged or freshly fractured silica increased PMN yield and AM activation above control. However, zymosan-stimulated and l-NAME sensitive AM chemiluminescence was greater for rats exposed to freshly fractured silica compared to aged silica. Exposure to 240 μg aged or freshly fractured silica also resulted in pulmonary damage, but the extent of this damage did not differ between the two types of silica. The results suggest that exposure of rats to silica levels far lower than those previously examined can cause pulmonary inflammation. In addition, exposure to freshly fractured silica causes greater generation of reactive oxygen species from AM, measured as AM chemiluminescence, in comparison to aged silica, but there is an apparent threshold below which this difference does not occur.

Comparative Pulmonary Responses Caused by Exposure to Standard Cobalt and Ultrafine Cobalt

Comparative Pulmonary Responses Caused by Exposure to Standard Cobalt and Ultrafine Cobalt: Qunwei Zhang, et al. Department of Environmental Health, School of Medicine, Fukui Medical University—The aim of this study was to compare the pulmonary toxicity after exposure to standard cobalt (Std‐Co) and ultrafine cobalt (Uf‐Co). Rats were intratracheally instilled with 1 mg of Std‐Co and Uf‐Co, and wet lung weight and bronchoalveolar lavage fluid (BALF) profiles were analysed 1,3,7,15 and 30 d later. The effects of Std‐Co and Uf‐Co on indices that can be presumed to reflect epithelial injury and permeability (lactate dehydrogenase (LDH) and total protein (TP)), and release of proinflammatory cytokine (tumor necrosis factor‐alpha (TNF‐alpha)) were increased throughout the 30 d post‐exposure period. The results showed that the effects of Std‐Co and Uf‐Co on these indices were significantly higher than those of control. The results also showed that the effects of Uf‐Co on indices were significantly higher than those of Std‐Co from 1 to 15 d after instillation. Moreover, the number of neutrophils and LDH activity in BALF in rats after exposure to Uf‐Co were significantly greater than those of Std‐Co‐exposed rats up to 30 d after instillation. Our findings suggest that Uf‐Co has a much more toxic effect on the lungs than Std‐Co, but the mechanism remains to be elucidated.

Evaluation of pulmonary toxicity of heavy metal compounds

The present report describes toxicological approaches to evaluate inflammatory potency of heavy metal compounds deposited in the lung. Although inhalation exposure is a well-accepted method to study effects of pulmonary toxicants, it requires expensive facilities and many man-hours to complete experiments. Intratracheal (i.t.) instillation, an alternative and simple method to expose animals to toxicants via airways, has been proved to be useful to investigate the pulmonary clearance of heavy metals. However, acute inhalation exposure caused more severe inflammatory lung injury than i. t. instillation when the same amount of nickel sulfate was administered in the rat. Among several biochemical inflammatory indices such as some enzyme activities and the protein concentration in bronchoalveolar lavage (BAL) fluid, only lactate dehydrogenase (LDH) activity increased linearly with a wide range of doses of heavy metals. The increase in polymorphonuclear leukocytes (PMN) in BAL fluid, a cytological index of inflammatory responses of the lung, is believed to reflect pulmonary toxicity of heavy metals. However, more extensive study is required to elucidate the mechanism of transpulmonary PMN infiltration upon heavy metal insult. In addition to the linearity between LDH activity in BAL fluid and doses of heavy metals, the increase in this cytosolic enzyme activity is associated with cell lysis in the bronchoalveolar milieu and appears to be the best index to evaluate pulmonary inflammatory potency of heavy metals.

Localization and health effects of lanthanum chloride instilled intratracheally into rats

Lanthanum (La) is one of the rare earths used in diverse high technology fields for which sufficient data for assessing its health effects have been lacking. The biological effects and metabolic behaviors of La were studied by instilling lanthanum chloride intratracheally into male Wistar rats. The distribution of La among tissues revealed that the metal remains mostly in the lung with a biological half-time of 244 days. The subcellular localization by transmission electron microscopy with an X-ray microanalyzer indicated that La localizes in macrophages as high electron-dense granular inclusions in lysosomes and on the cell surface and basement membranes of type I pneumocytes among lung cells. The pulmonary health effects were examined by biological indices of the bronchoalveolar lavage fluid (BALF) and lung tissue. The acute toxicity estimated by lactate dehydrogenase activity in BALF was comparable to those of yttrium and copper that had been determined under the same protocol. Microscopic examination of the lung indicated a characteristic increase in the number of eosinophils.

Development of morphologic, hemodynamic, and biochemical changes in lungs of rats given monocrotaline pyrrole

A single, intravenous administration of a low dose of monocrotaline pyrrole (MCTP), a derivative of the pyrrolizidine alkaloid monocrotaline (MCT), induces progressive pulmonary hypertension and right ventricular hypertrophy (RVH) in rats. The temporal relationship between morphologic alterations, biochemical markers of lung injury, and the development of pulmonary hypertension was determined during the developing pulmonary disease. Three days after a single iv injection of 3.5 mg/kg MCTP, small increases in bronchoalveolar lavage (BAL) fluid lactate dehydrogenase (LDH) activity and accumulation in the lungs of intravenously administered 125I-bovine serum albumin (BSA) were associated with minimal to mild interstitial edema around large airways and blood vessels. By Day 5, BAL fluid LDH activity and 125I-BSA accumulation had increased further, and lung weight/body weight ratio and BAL fluid protein concentration were greater than those of control. Interstitial edema was more pronounced and involved patches of alveolar septal walls. A mild increase in numbers of mononuclear cells, including hypertrophied interstitial cells, was evident in these areas. Walls of pulmonary arteries less than 60 μm in diameter were mildly thickened. By Day 8, scattered clusters of alveolar sacs contained serous exudate, and interstitial mononuclear infiltrates were more pronounced. Mild to moderate thickening of arterial walls was apparent in small and large vessels. By Day 14, pulmonary arterial pressure was elevated and RVH was evident. Arterial walls were thickened and had hypertrophy of medial smooth muscle cells and intercellular edema, which was particularly prominent in areas with perivascular interstitial inflammation. Large patches of lung interstitium and alveolar lumens contained serous or fibrinous exudate. In summary, a single, intravenous administration of MCTP induced a delayed and progressive pulmonary microvascular leak, interstitial inflammation, and alterations in muscular blood vessels which resulted in pulmonary hypertension within 14 days. These morphologic, biochemical, and hemodynamic changes are nearly identical to alterations induced by the parent alkaloid. MCT.