In order to observe the effects of serum albumin and fibrinogen on biophysical surface properties and the morphology of pulmonary surfactant in vitro, we measured the surface adsorption rate, dynamic minimum and maximum surface tension (min-, max-ST) by Pulsating Bubble Surfactometer, and demonstrated ultrastructures on a series of mixtures with varying concentrations of albumin or fibrinogen and Surfactant-TA. The albumin and fibrinogen significantly inhibited the adsorption rate and ST-lowering properties of surfactant through increasing STs of adsorption rate, min-ST, and max-ST. The characteristic morphology of the Surfactant-TA changed from lamellar rod-like structure with open ends into spherical structures with loss of their open ends by mixing with albumin or fibrinogen. These inhibitory effects of albumin and fibrinogen on surface properties of surfactant were dependent upon the increasing concentration of albumin or fibrinogen. We concluded that albumin and fibrinogen significantly altered surfactant function and its ultrastructural morphology in vitro. These findings support the concept that albumin and fibrinogen-induced surfactant dysfunction may play an important role in the pathophysiology of adult respiratory distress syndrome, and this adverse effect of albumin and fibrinogen on surfactant might be overcome by administration of large doses of exogenous surfactant.
Adsorption ; Animal ; Cattle ; Fibrinogen/pharmacology* ; Human ; Pulmonary Surfactants/ultrastructure* ; Pulmonary Surfactants/drug effects ; Serum Albumin, Bovine/pharmacology* ; Surface Properties

OBJECTIVETo investigate the protective and therapeutic effects of pulmonary surfactant in the pathogenesis of chronic obstructive pulmonary disease (COPD) in hamsters.

METHODSCOPD animal model was established by smoke inhalations and intratracheal instillations of pancreatic elastase in hamsters. Ninty hamsters were divided into 9 groups as follows: normal group (N), two groups received smoke inhalations for 1 and 3 months (S1 and S3), one group received intratracheal instillation of surfactant (10 mg/100 g BW) for once after 1 month smoking (SP1), one group was treated with surfactant after 1.5, 2 and 2.5 months of smoking (SP3), and two groups received intratracheal administration of elastase (40 U/100 g BW) and were killed after 1 month and 3 months, respectively (E1 and E3). The surfactant was injected intratracheally after 1 week, 0.5, 1.0, 1.5, 2.0, and 2.5 months, followed by administration with elastase (EP1 and EP3). EP1 group were killed at the first month, and EP3 at the third month. Light microscopy and electromicroscopy observations were performed in each group. Pulmonary mean linear intercept (MLI), mean alveolar numbers (MAN), and pulmonary alveolar area (PAA) was measured by image analysis. The expression of surfactant protein A (SP-A) were observed by immunohistochemistry.

RESULTSSmoking for 3 months and instillations of elastase resulted in chronic bronchitis and emphysema. MLI and PAA increased and MAN decreased in all the experimental groups compared with in the normal group (P < 0.05 or P < 0.01). Administration of surfactant for 3 months resulted in statistically significant inhibition of pulmonary injury. MLI and PAA decreased and MAN increased in SP3 compared with in S3. Only MLI decreased in EP3 compared with E3. The expressions of SP-A in the type II alveolar epithelia decreased in S3 and E3 (compared with the normal group P < 0.01). After pulmonary surfactant intervention, the expression of SP-A increased significantly.

CONCLUSIONPulmonary surfactant may have a long-term protective effect on chronic smoking and elastase-induced COPD.

Animals ; Cricetinae ; Male ; Mesocricetus ; Pancreatic Elastase ; Pulmonary Alveoli ; ultrastructure ; Pulmonary Disease, Chronic Obstructive ; metabolism ; prevention & control ; Pulmonary Surfactant-Associated Protein A ; metabolism ; Pulmonary Surfactants ; therapeutic use ; Smoking

OBJECTIVETo observe the ultrastructures of rat alveolar type II cells and change of composition of phospholipid(PL) and content of protein in pulmonary surfactant(PS), to investigate the relation between change in composition of PL and activity of alveolar type II cells.

METHODSThe rats lung injury models were made by intratracheally instilling bleomycin(BLM) (4 mg/ml, 5 mg/kg). 28 rats were divided into four groups: 3-day group, 7-day group, 14-day group and 28-day group. Preparations of each group were stained histochemically and examined by electron microscope, content of PL in BALF, composition of PL and content of protein of each group were determined respectively.

RESULTS(1) Rats lungs in experimental groups were found that PS lost continuously, appeared homogenous and chorionic, dropped in the pulmonary alveolies. 3-day group was more apparent. Ruthenium red attaching on pulmonary surfactant was thicker in 3-day group, and the colour deeper, no difference in 7-day group and 14-day group, thinner in 28-day group. Content of PL in PS of BALF was increasing. Content of phosphatidylglycerol(PG) increased in 3-day group, decreased in 7-day, 14-day and 28-day group. The change of content of phosphatidylinositol(PI) was reversed. (2) Alveolar type II cells degenerated, necrotized, even disintegrated in 3-day group and 7-day group. 3-day group was more apparent. Proliferations of alveolar type II cells were found in each group, 7-day group was more apparent. We found that type II cells transformed to type I cells in 14-day group, extended and attached on bare basement membrane. Content of protein in PS was the highest in 3-day group, almost equal to the content of the control group in 28-day group.

CONCLUSIONMorphologic change and alternation of quality and quantity of PS after bleomycin-induced pulmonary injures specifically reflect the activity of alveolar type II cells. Measuring content of PL in BALF is one of simple and feasible method judging activity of alveolar type II cells when lungs of the rats are injured early by bleomycin.

Animals ; Antibiotics, Antineoplastic ; toxicity ; Bleomycin ; toxicity ; Bronchoalveolar Lavage Fluid ; chemistry ; Lung ; drug effects ; pathology ; ultrastructure ; Pulmonary Alveoli ; chemistry ; Pulmonary Surfactants ; analysis ; Rats

OBJECTIVETo observe the effect of intra-amniotic administration of pulmonary surfactant (PS) on the lung ultrastructure and expression of surfactant protein A (SP-A) in fetal rabbit with intrauterine infection.

METHODSIntra-amniotic PS injection was administered in a rabbit model of premature rupture of membrane and intrauterine infection induced by intrauterine colibacillus injection on the gestational days 24 and 26 days. The lung ultrastructural changes in the fetal rabbits were observed using electron microscope, and the expression of SP-A was measured with immunohistochemical staining and Western blotting 19.5 h after the PS administration.

RESULTSalveolar type I cell (AT I), alveolar type II cell (AT II). In fetal rabbits with intrauterine colibacillus injection, inflammatory cell infiltration was observed in the pulmonary alveolus, bronchus lumens and intracytoplasm irrespective of PS administration. Compared with those in normal fetal rabbits, the number of alveolar type II cells (AT II) in the lung tissue decreased in fetal rabbits with intrauterine infection, and vacuolization of the lamellar bodies occurred with evidence of cell apoptosis; PS administration resulted in increased number of the AT II cells and lamellar bodies and reduced the cell apoptosis. The expression of SP-A was significantly lower in the infection group than in normal control group (P<0.05), but comparable between the PS group and the control group (P>0.05).

CONCLUSIONChanges in pulmonary alveolar ultrastructure and decreased expression of SP-A occur in fetal rabbits after intrauterine infection, and intra-amniotic administration of PS can alleviate these changes to promote lung maturation.

Amnion ; Animals ; Female ; Fetal Membranes, Premature Rupture ; drug therapy ; Injections ; Lung ; embryology ; metabolism ; ultrastructure ; Pregnancy ; Pregnancy Complications, Infectious ; metabolism ; Pulmonary Surfactant-Associated Protein A ; metabolism ; Pulmonary Surfactants ; administration & dosage ; Rabbits