[Alterations of pulmonary surfactant during Pseudomonas aeruginosa pneumonia of immunocompromised rats].
OBJECTIVE
To analyze the alterations of pulmonary surfactant in immunocompromised host with Pseudomonas aeruginosa (PA) pneumonia.


METHODS
50 rats were randomly divided into two groups, one immunosuppressed with cyclophosphamide and cortisone acetate as ICH group, another as control group (CON), their lung tissue and bronchoalveolar lavage fluid (BALF) were collected before PA challenging and 3 h, 6 h, 9 h, 24 h after PA challenging intratracheally, wet/dry ratio (W/D) of lung tissue were measured, concentrations of total protein (TP), total phospholipids (TPL), disaturated phosphatidylcholine (DSPC) and surfactant protein A (SP-A) in BALF were analyzed.


RESULTS
The ratios of DSPC/TPL and DSPC/TP decreased significantly in both ICH and CON groups after PA infection, there were not significant differences between the two groups, no change in the concentrations of TPL and DSPC. Concentration of SP-A and SP-A/TP in ICH group decreased remarkably 6 h after PA pulmonary infection than before [(1.8 +/- 1.1) microgram/ml vs (4.2 +/- 1.5) microgram/ml, (1.4 +/- 0.7) microgram/mg vs (11.7 +/- 8.1) microgram/mg, P < 0.05], meanwhile there were no significant alterations in CON group. W/D and TP concentrations increased in both groups after PA challenging, however the alterations were much greater in ICH group (P < 0.05). Alterations of SP-A appeared a negative correlation with alterations of TP and W/D (r = -0.793, P < 0.01, r = -0.769, P < 0.01). The ratios of SP-A/TPL and SP-A/DSPC decreased significantly 6 h after PA challenging than before, the ratios were much lower in ICH group than in CON group during 6 h-9 h after PA inoculation.


CONCLUSIONS
After PA pulmonary infection, alterations of phospholipids could initially appear a relative decrement of DSPC during acute phase of infection, much remarkable decrease of SP-A in ICH group could be associated with the more severe lung injury, alterations of SP-A were more obvious than surfactant lipids in ICH.
Li
Z
Z
Department of Pulmonary Medicine, Zhongshan Hospital, Institute of Respiratory Diseases, Medical Center of Fudan University, Shanghai 200032, China.
Qu
J
J
He
L
L
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D003348:Cortisone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000494:pharmacology; D004195:Disease Models, Animal; D016867:Immunocompromised Host / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D010713:Phosphatidylcholines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D018410:Pneumonia, Bacterial / Q000276:immunology* / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011510:Proteolipids / Q000276:immunology* / Q000378:metabolism; D011552:Pseudomonas Infections / Q000276:immunology* / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000276:immunology; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000276:immunology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D007166:Immunosuppressive Agents; D010713:Phosphatidylcholines; D010743:Phospholipids; D011506:Proteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; C017463:lecithins, disaturated; D003520:Cyclophosphamide; D003348:Cortisone