• Applied Microscopy
• /
• v.31 no.1
• /
• pp.71-83
• /
• 2001

Laminin, a kind of multidomain glycoproteins, is mainly localized in the basement membranes of various tissues. It is known that laminin plays an important part in mammalian lung morphogenesis. The authors have undertaken this study to investigate the changes in the distribution of laminin, and to find out cells which synthesize laminin during the organogenesis and differentiation of the lung. The fetal and neoantal rats (Sprague-Dawley strain) were used as experimental animals. The immunohisto-chemical methods were employed for detection of laminin within the developing lung tissue and the immunegold cytochemical methods were performed for detection of cells which synthesize laminin according to each stage of development. The results are as follows; 1. During fetal life, strong immunoreactivity for laminin is maintained in the basement membranes of the blood vessels and the bronchioles, the extracellular matrix of the mesenchyme, and basal lamina of the alveolar septum in the fetal rat lung. 2. After birth, laminin immunoreactivity at the alveolar septum is gradually reduced. 3. During fetal life, laminin is mainly detected within the cytoplasm of the mesenchymal cells, the endothelial cells of blood vessels and the fibroblasts in fetal rat lung. 4. According to the differentiation of type I and type II pneumocyte after birth, laminin is detected within cytoplasm of the type I pneumocytes, type II pneumocytes and fibroblasts. It is consequently suggested that laminin is largely expressed in the developing lung and laminin may be also synthesized by the type II pneumonocytes at early newborn stages.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.2
• /
• pp.184-205
• /
• 1995

Background: Pulmonary toxicity by bleomycin has multiple mechanisms including direct tissue toxicity due to oxygen-derived free radicals and indirect toxicity through amplification of pulmonary inflammation. To evaluate the effect of chelators or free radical scavenger to lung damage induced by bleomycin, penicillamine as a copper chelator, deferoxamine as an iron chelator and vitamin E as a free radical scavenger were administered. Methods: Two hundred Wistar rats were divided into five groups: Control, bleomycin treated, bleomycin-penicillamine treated, bleomycin-deferoxamine treated, and bleomycin-vitamin E treated groups. Rats sacrificed on day 1, day 3, day 4, day 7, day 14, and day 28 after treatment. Bronchoalveolar lavage, light microscopic and immunohistologic studies for type I, III, IV collagens, fibronectin, laminin and NBD phallicidin were evaluated. Results: There was a significant increase in the total cell counts of bronchoalveolar lavage on day 1 from all treated animals and vitamin treated group showed an abrupt decrease in total cell counts with decrease of neutrophils on day 3. Bleomycin-vitamin E treated group had the least histologic changes such as pulmonary fibrosis. The alveolar basement membranes were positive for type IV collegen and laminin. Basement membranes of bleomycin, bleomycin-penicillamine, or bleomycin-deferoxamine treated groups were disrupted and fragmented on day 4 or 7. The bleomycin-vitamin E treated group had intact basement membranes until day 28. Conclusion: Bleomycin-induced pulmonary fibrosis was related to the severity of acute injury to oxygen radicals or activation of neutrophils and disruption of basement membrane. Vitamin E seemed to be the most effective antioxidant in the inhibition of bleomycin-induced pulmonary injury and fibrosis.

• Tuberculosis and Respiratory Diseases
• /
• v.59 no.4
• /
• pp.397-405
• /
• 2005

Background : Laminin-1 is known to have regular functions in the development and course of differentiation of the lungs. The morphogenesis and distribution of laminin-1 still remains as a mystery and its distribution and changes in the molecular structure of laminin-1 in the pathogenesis of the lung still is a subject of great controversy. In this study, experiments were done to delineate the distribution and changes in the amount of laminin-1 after inducing inflammation of the lungs by exposing experimental animals to CS gas and especially, to find compositions of laminin-1 within type II pneumocytes. Materials and Methods : The experimental subjects of study were newborn rats and the extracted tissue from the experimental rats were viewed under light microscope and electron microscope after the sections were treated with immunohistochemical methods and immunogold reaction methods using bounded gold particles. Results : 1) Lymphocytes and mononuclear phagocytes invaded the alveolar septa in the 2 day group rats after CS gas exposure and intense interstitial inflammation was seen in the 3 day group. 2) Laminin immunoreactions decreased to a moderate degree in the 2 and 3 day group rats after CS gas exposure and strong laminin immunoreactions were seen again in the 5 and 7 day group rats. 3) Gold particles in basal lamina of the lung blood-air barrier decreased and in the type I pneumocytes decreased in the 2 and 3 day group rats after CS gas exposure. 4) Gold particles were seen only on the surface of the cell membranes of type II pneumocytes of the 1 and 2 day group rats after CS gas exposure. 5) Few gold particles around the lamellar bodies and cytoplasm of type II pneumocytes in the control rat group and at 12 hours after CS gas exposure. Gold particles are seen only on the surface of type II pneumocytes of the 1 and 2 day group rats after CS gas exposure and are evenly distributed in small amounts in the cells of the 3 day group after CS gas exposure. Conclusion : CS gas exposure in the rats caused inflammation of lung alveolar septa and also induced a decrease in laminin-1 in basal lamina and loss of laminin-1 in the cytoplasm of type II pneumonocytes. As the inflammatory cells disappeared, an increase in the distribution of laminin-1 occurred. This reflects tissue regeneration functions of laminin-1 in the pneumocytes of rats and the distribution of laminin-1 in type II pneumocytes can be seen through the electron microscope using immunogold methods.

• Applied Microscopy
• /
• v.24 no.1
• /
• pp.77-85
• /
• 1994

In order to investigating the pulmonary toxicity of the O-chlorobenzyledene malononitrile (CS), lacrimating agent, $2.6g/m^3$ of CS was inhalated to Sprague-Dawley rats in the plastic chamber for 20 minutes. The ultrastructural changes of type II pneumocytes in the lung were observed with Hitachi 600 transmission electron microscope. The results obtained were as follows: 1. 3 hours after exposure to CS the fusion of surface microvilli, dilatation of cristernae of the rough endoplasmic reticulum, atrophy of Golgi complex and condensation, deletion of lamellated membranes in lamellar bodies were observed in type II pneumocytes. 2. One and 2 days after CS-exposure, disorganization of mitochondrial double membranes, fragmentations of rough endoplasmic reticulum were found in the great alveolar cells. In addition, decrease in amount of polyribosome granules and deletion or condensation of lamellated membranes in lamellar bodies were also observed. 3. 4 days after exposure to CS, the type II pneumocyte revealed new whorled lamellar membranes in lamellar bodies, a few intact rough endoplasmic reticulum and restoration of polyribosome granules. It is consequently suggested that CS induces degenerative changes of cytoplasmic organelles in the type II pneumocytes.

• The Korean Journal of Physiology
• /
• v.8 no.2
• /
• pp.49-53
• /
• 1974

A single dose of pilocarpine was subcutaneously injected into the rabbit in order to clarify the effects of cholinergic activities on the secretion of the pulmonary surfactant. The animal was sacrificed four hours after the injection, and the pressure-volume curve of the excised lung was obtained. The surfactant activities of the lung washings were also measured, and a comparison was made with the normal. The pressure-volume curve of the excised lung by the injection and ejection of air formed a loop (hysteresis) and the mean intra-alveolar pressure at 35 ml of air was 220 $mmH_20$ in the normal. The mean deflation curve of the pilocarpine treated rabbit lungs was shifted to the left compared with the normal. The surfactant activities were slightly increased than the normal. The above results suggest that pilocarpine stimulates the secretion of the pulmonary surfactant from the Type II alveolar epithelial cell.

• Applied Microscopy
• /
• v.29 no.2
• /
• pp.137-147
• /
• 1999

Comparative differences between the fine structure of cultured LL/2 cell in vitro and tumor cells in vivo which were induced in the lung by inoculation of LL/2 cells to C57 BL/6 mouse via tail vein during 21 days are not observed except for cell configuration which was changed spindle shape into oval shape. At first tumor cells appeared at lymphatic nodules and around capillary in the lung. Tumor cells divided actively by mitosis, so they became tumor nodules. The pulmonary aveoli around tumor nodules were observed somewhat flattened in shape but the cells in the aveoli appeared to be in normal condition. Furthermore the normal lung cells were observed in the tumor nodules and some apoptotic tumor cells appeared in the large tumor nodules. A lot of neutropiles were observed in the aveoli and tumor nodules of C57 BL/6 mouse lung after inoculation 22 days and 31days.

• Journal of Yeungnam Medical Science
• /
• v.1 no.1
• /
• pp.59-66
• /
• 1984

Although it is well established that steroid is effective for treatment of neonatal respiratory distress syndrome (NRDS), the action mechanism of steroid on NRDS is not well known. Several authors have insisted that steroid increases secretion of pulmonary surfactant from type II pneumocyte, but others have insisted that steroid does not affect the secretory function of the type II pneumocyte. And some authors have suggested that steroid may ca use compositional change of pulmonary surfactant phospholipid. From these aspects, it is desirable to confirm the effect of steroid on (he secretory function of the type II pneumocyte. In order to know the effect of steroid on pulmonary surfactant activity, phospholipid phosphorus of lung lavage was measured and composition of pulmonary surfactant phospholipid of lung lavage was analyzed by thin layer chromatography (TLC) in control (C), pneumonectomized (PN), and pneumonectomized with betamethasone treated (PNS) rabbits. And lung weight and lung weight-body weight ratio were measured in each experimental group also. In PN group, right lung pneumonectomy was performed under general anesthesia with pentobarbital sodium (30mg/kg). On the fifth day after the surgery, the left lung was excised and measured above parameters. In PNS group, pneumonectomy was performed as PN group, and one day after the surgery, betamethasone was injected for four days intramusculary (4mg/day) and rabbits were sacrificed. The experiment yielded following results. PNS group's lung weight was significantly (p<0.01) heavier than C group's, but in comparison with PN group's it showed no significant change. PNS group's L/B ratio was significantly (p<0.05) higher than C group's, but compared with PN group's it showed no significant change. The value of phospholipid phosphorus content of PNS group was significantly (p<0.01) higher than that of C group. Even if the value of phospholipid phosphorus content in PNS group was not significantly higher than that of PN group, it showed increasing tendency compared with that of PN group. And in an analysis of the thin layer chromatogram, quantity (${\mu}mol/gm$ of wet weight lung) of phosphatidylcholine in PNS group decreased significantly (p<0.05) compared with C and PN group. From these results, it may be suggested that though steroid inhibits cellular hyperplasia in the compensatory growing lung, it auguments the secretory function of type II pneumocyte and causes compositional change of pulmonary surfactant phospholipid.

• Journal of Life Science
• /
• v.21 no.8
• /
• pp.1100-1108
• /
• 2011

The immunomodulating effects of moxifloxacin seem to be effective in downregulating inflammatory reactions. This presumed effect was tested in endotoxin (ETX)-induced acute lung injury (ALI) in rats. After moxifloxacin treatment (10 mg/kg) of ETX-given rats, lung myeloperoxidase (MPO) activity, bronchoalveolar-lavage (BAL) protein, and the number of neutrophils in the BAL cells were measured. Light and electron microscopic structures were also examined. Electron microscopic $CeCl_3$ histochemistry for the detection of hydrogen peroxide in the lungs and immunohistochemistry of cytosolic phospholipase A2 (cPLA2) in the lung tissues and BAL cells were performed. To examine the expression of TNF${\alpha}$ in the lungs, western blotting was carried out with the lung tissues. ETX had accumulated neutrophils in the lungs, which was followed by lung leak. Oxidative stress occurred, and increased expression of cPLA2 in the lung tissues and BAL cells was observed in the ETX-given rats. Simultaneously, the expression of TNF${\alpha}$ was enhanced by ETX. Moxifloxacin, however, decreased all these parameters, indicating that ALI may have been ameliorated. Moxifloxacin appears to ameliorate ETX-induced ALI partially through the suppression of cPLA2 in the lungs of rats.

• Applied Microscopy
• /
• v.33 no.1
• /
• pp.1-16
• /
• 2003

As is well known that N-nitroso-N-methylurethane (NNNMU) causes acute lung injury (ALI) in experimental animals. And ALI caused by NNNMU is very similar to ARDS in human being in its pathology and progress. In its context, we investigated the pathogenetic mechanism of ARDS associated with oxidative stress by neutrophils in Sprague-Dawley rat model of NNNMU-induced ALI. NNNMU had increased lung weight/body weight ratio (L/B ratio), lung myeloperoxidase (MPO) activity, protein content and number of neutrophils in bronchoalveolar fluid (BALF) compared with those of control rat (p<0.001, respectively). In contrast, the amount of pulmonary surfactant in BALF was decreased by NNNMU (p<0.001). Morphologically, light microscopic examination denoted pathological findings such as formation of hyaline membrane, infiltration of neutrophils and perivascular cuffing in the lungs of NNNMU-treated rats. In addition, ultrastructural changes such as the necrosis of endothelial cells, swelling and vacuolization of lamellar bodies of alveolar type II cells, and the degeneration of pulmonary surfactant were identified after treatment of NNNMU. Very interestingly, cerium chloride electron microscopic cytochemistry showed that NNNMU had increased the production of cerrous-peroxide granules in the lung, which signified the increased production of hydrogen peroxide in the lung. Collectively, we conclude that NNNMU causes acute lung leak by the mechanism of neutrophilic oxidative stress of the lung.

• Journal of Life Science
• /
• v.22 no.3
• /
• pp.298-305
• /
• 2012

The general term flavonoids is often used to categorize a family of natural compounds that are highly abundant in all higher plants, and which in recent years have attracted scientific interest as therapeutics. Lutein is a xanthophyll and one of 600 known naturally occurring carotenoids. It is found in green vegetables such as spinach and kale, and has been demonstrated to exert anti-inflammatory activities. However, its anti-allergic effect in the Th1/Th2 immune response is poorly understood. In this study, we attempt to determine whether lutein regulates inflammatory mediators in an ovalbumin (OVA)-induced murine asthma model. To address this, mice were sensitized and challenged with OVA, and then treated with lutein before the last OVA challenge. Administration of lutein significantly suppressed the OVA-induced airway hyper-responsiveness. It also resulted in a significant alleviation of the infiltration of inflammatory cells into the bronchoalveolar lavage. Additionally, lutein attenuated the increased expression of Th2 responses in OVA-challenged mice. These results demonstrate that lutein is a potent inhibitor that reduces Th2 immune responses. Furthermore, they show that the immunopharmacological function is mediated by a pathway that involves and is regulated by Th2 immune response.