scholarly journals Effects of chronic l-NAME treatment lung tissue mechanics, eosinophilic and extracellular matrix responses induced by chronic pulmonary inflammation

2008 ◽  
Vol 294 (6) ◽  
pp. L1197-L1205 ◽  
Author(s):  
Patrícia Angeli ◽  
Carla M. Prado ◽  
Débora G. Xisto ◽  
Pedro L. Silva ◽  
Caroline P. Pássaro ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Lung Tissue ◽  
Pulmonary Inflammation ◽  
Elastic Fiber ◽  
Tissue Mechanics ◽  
Elastic Fibers ◽  
Distal Lung ◽  
Alveolar Septa

The importance of lung tissue in asthma pathophysiology has been recently recognized. Although nitric oxide mediates smooth muscle tonus control in airways, its effects on lung tissue responsiveness have not been investigated previously. We hypothesized that chronic nitric oxide synthase (NOS) inhibition by Nω-nitro-l-arginine methyl ester (l-NAME) may modulate lung tissue mechanics and eosinophil and extracellular matrix remodeling in guinea pigs with chronic pulmonary inflammation. Animals were submitted to seven saline or ovalbumin exposures with increasing doses (1∼5 mg/ml for 4 wk) and treated or not with l-NAME in drinking water. After the seventh inhalation (72 h), animals were anesthetized and exsanguinated, and oscillatory mechanics of lung tissue strips were performed in baseline condition and after ovalbumin challenge (0.1%). Using morphometry, we assessed the density of eosinophils, neuronal NOS (nNOS)- and inducible NOS (iNOS)-positive distal lung cells, smooth muscle cells, as well as collagen and elastic fibers in lung tissue. Ovalbumin-exposed animals had an increase in baseline and maximal tissue resistance and elastance, eosinophil density, nNOS- and iNOS-positive cells, the amount of collagen and elastic fibers, and isoprostane-8-PGF2α expression in the alveolar septa compared with controls ( P < 0.05). l-NAME treatment in ovalbumin-exposed animals attenuated lung tissue mechanical responses ( P < 0.01), nNOS- and iNOS-positive cells, elastic fiber content ( P < 0.001), and isoprostane-8-PGF2α in the alveolar septa ( P < 0.001). However, this treatment did not affect the total number of eosinophils and collagen deposition. These data suggest that NO contributes to distal lung parenchyma constriction and to elastic fiber deposition in this model. One possibility may be related to the effects of NO activating the oxidative stress pathway.

Lung tissue mechanics and extracellular matrix composition in a murine model of silicosis

2001 ◽  
Vol 90 (4) ◽  
pp. 1400-1406 ◽  
Author(s):  
Débora S. Faffe ◽  
Gabriela H. Silva ◽  
Pedro M. P. Kurtz ◽  
Elnara M. Negri ◽  
Vera L. Capelozzi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Lung Tissue ◽  
Elastic System ◽  
Elastic Fiber ◽  
Dynamic Mechanical Properties ◽  
Tissue Mechanics ◽  
Matrix Composition ◽  
Elastic Fibers ◽  
Oxytalan Fibers

The dynamic mechanical properties of lung tissue and its contents of collagen and elastic fibers were studied in strips prepared from mice instilled intratracheally with saline (C) or silica [15 (S15) and 30 days (S30) after instillation]. Resistance, elastance, and hysteresivity were studied during oscillations at different frequencies on S15 and S30. Elastance increased from C to silica groups but was similar between S15 and S30. Resistance was augmented from C to S15 and S30 and was greater in S30 than in S15 at higher frequencies. Hysteresivity was higher in S30 than in C and S15. Silica groups presented a greater amount of collagen than did C. Elastic fiber content increased progressively along time. This increment was related to the higher amount of oxytalan fibers at 15 and 30 days, whereas elaunin and fully developed elastic fibers were augmented only at 30 days. Silicosis led not only to pulmonary fibrosis but also to fibroelastosis, thus assigning a major role to the elastic system in the silicotic lung.

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs

2008 ◽  
Vol 104 (6) ◽  
pp. 1778-1785 ◽  
Author(s):  
Adriane S. Nakashima ◽  
Carla M. Prado ◽  
Tatiana Lanças ◽  
Viviane C. Ruiz ◽  
David I. Kasahara ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lung Tissue ◽  
Guinea Pigs ◽  
Oral Tolerance ◽  
Elastic Fiber ◽  
Allergic Inflammation ◽  
Tissue Mechanics ◽  
Fiber Content ◽  
Extracellular Matrix Remodeling ◽  
Matrix Remodeling

Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1–5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.

Elastin exhibits a distinctive temporal and spatial pattern of distribution in the developing chick limb in association with the establishment of the cartilaginous skeleton

1994 ◽  
Vol 107 (9) ◽  
pp. 2623-2634 ◽  
Author(s):  
J.M. Hurle ◽  
G. Corson ◽  
K. Daniels ◽  
R.S. Reiter ◽  
L.Y. Sakai ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Spatial Pattern ◽  
Elastic Fiber ◽  
Spatial Location ◽  
Limb Bud ◽  
Confocal Laser ◽  
Elastic Fibers ◽  
Type I ◽  
Temporal And Spatial

In this work we have analyzed the presence of elastic components in the extracellular matrices of the developing chick leg bud. The distributions of elastin and fibrillin were studied immunohistochemically in whole-mount preparations using confocal laser microscopy. The association of these constituents of the elastic matrix with other components of the extracellular matrix was also studied, using several additional antibodies. Our results reveal the transient presence of an elastin-rich scaffold of extracellular matrix fibrillar material in association with the establishment of the cartilaginous skeleton of the leg bud. The scaffold consisted of elastin-positive fibers extending from the ectodermal surface of the limb to the central cartilage-forming regions and between adjacent cartilages. Fibrillin immunolabeling was negative in this fibrillar scaffold while other components of the extracellular matrix including: tenascin, laminin and collagens type I, type III and type VI; appeared codistributed with elastin in some regions of the scaffold. Progressive changes in the spatial pattern of distribution of the elastin-positive scaffold were detected in explant cultures in which one expects a modification in the mechanical stresses of the tissues related to growth. A scaffold of elastin comparable to that found in vivo was also observed in high-density micromass cultures of isolated limb mesodermal cells. In this case the elastic fibers are observed filling the spaces located between the cartilaginous nodules. The fibers become reoriented and attach to the ectodermal basal surface when an ectodermal fragment is located at the top of the growing micromass. Our results suggest that the formation of the cartilaginous skeleton of the limb involves the segregation of the undifferentiated limb mesenchyme into chondrogenic and elastogenic cell lineages. Further, a role for the elastic fiber scaffold in coordinating the size and the spatial location of the cartilaginous skeletal elements within the limb bud is also suggested from our observations.

Recombinant human superoxide dismutase reduces lung injury caused by inhaled nitric oxide and hyperoxia

1997 ◽  
Vol 272 (5) ◽  
pp. L903-L907 ◽  
Author(s):  
C. G. Robbins ◽  
S. Horowitz ◽  
T. A. Merritt ◽  
A. Kheiter ◽  
J. Tierney ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Lung Tissue ◽  
Pulmonary Inflammation ◽  
Inhaled Nitric Oxide ◽  
Newborn Piglets ◽  
Markers Of Inflammation ◽  
Cell Counts

We previously demonstrated that 48 h of 100 ppm inhaled nitric oxide (NO) and 90% O2 causes surfactant dysfunction and pulmonary inflammation in mechanically ventilated newborn piglets. Because peroxynitrite (the product of NO and superoxide) is thought to play a major role in the injury process, recombinant human superoxide dismutase (rhSOD, a scavenger of superoxide) might minimize this insult. Four groups of newborn piglets (1-3 days of age) were ventilated with 100 ppm NO and 90% O2 for 48 h. Piglets received no drug, 5 mg/kg rhSOD intratracheally at time 0, 5 mg/kg rhSOD intratracheally at 0 and 24 h, or 10 mg/kg rhSOD by nebulization at time 0. At 48 h, bronchoalveolar lavage (BAL) was performed, and lung tissue was analyzed for markers of inflammation, oxidative injury, acute lung injury, and surfactant function. There were significant differences between rhSOD-treated piglets and untreated controls with respect to BAL neutrophil chemotactic activity, cell counts, and protein concentration as well as lung tissue malondialdehyde concentrations. Minimum surface tension of BAL surfactant from all groups studied was increased, with no differences found among groups. These data suggest that rhSOD, at the doses used, mitigated the inflammatory changes, oxidative damage, and acute lung injury from exposure to 100 ppm NO and 90% O2 but did not appear to improve surfactant function. This has important clinical implications for infants treated with hyperoxia and NO for neonatal lung disorders.

scholarly journals Histological analysis of elastic cartilages treated with alkaline solution

2020 ◽  
Vol 72 (3) ◽  
pp. 647-654
Author(s):  
K.D. Ferreira ◽  
L.D. Cardoso ◽  
L.P. Oliveira ◽  
V.S. Franzo ◽  
A. Pancotti ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Alkaline Solution ◽  
Histological Analysis ◽  
Elastic Fiber ◽  
Peripheral Region ◽  
Cell Counting ◽  
Elastic Fibers ◽  
Fibrous Proteins ◽  
Fibrous Protein ◽  
Areas Of Interest

ABSTRACT The elastic cartilage is composed by chondroblasts and chondrocytes, extracellular matrix and surrounded by perichondrium. It has a low regeneration capacity and is a challenge in surgical repair. One of obstacles in engineering a structurally sound and long-lasting tissue is selecting the most appropriate scaffold material. One of the techniques for obtaining biomaterials from animal tissues is the decellularization that decreases antigenicity. In this work, alkaline solution was used in bovine ear elastic cartilages to evaluate the decellularization and the architecture of the extracellular matrix. The cartilages were treated in alkaline solution (pH13) for 72 hours and lyophilized to be compared with untreated cartilages by histological analysis (hematoxylin-eosin, Masson's trichrome and Verhoeff slides). Areas of interest for cell counting and elastic fiber quantification were delineated, and the distribution of collagen and elastic fibers and the presence of non-fibrous proteins were observed. The results demonstrated that the alkaline solution caused 90% decellularization in the middle and 13% in the peripheral region, and maintenance of the histological characteristics of the collagen and elastic fibers and non-fibrous protein removal. It was concluded that the alkaline solution was efficient in the decellularization and removal of non-fibrous proteins from the elastic cartilages of the bovine ear.

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