Effect of anti-C5a antibody on blood-lung and blood-brain barrier in rabbits after decompression.
The complement activation product C5a may be an important mediator of tissue injury after decompression stress. This study investigated whether the administration of anti-C5a antibody may reduce changes after decompression in the lung and in the brain. Two groups of rabbits were used; one receiving anti-C5a monoclonal antibody (n = 7) and the other receiving a sham antibody as control (n = 7) before pressure exposure. Five rabbits (4 in the anti-C5a group and 1 in the control group) died during the 2-h observation period postdive due to massive bubbling. Polymorphonuclear leukocyte (PMN) infiltration of lung tissue and pulmonary edema was observed, but this accumulation was unaffected by anti-C5a pretreatment. However, a significant positive correlation was observed between PMN accumulation and survival time postdive. Brain-specific gravity was lower for the group treated with anti-C5a antibody compared to the control group. Further, it was lower for those rabbits that died early compared to the ones that survived the 2-h period. This study was unable to prove a protective effect on the blood-brain and blood-lung barrier by injecting anti-C5a antibody. A possible beneficial effect of anti-C5a antibody may be masked by the mechanical damage caused by the gas bubbles.
Hjelde
A
A
Department of Physiology and Biomedical Engineering, Norwegian University of Science and Technology, Trondheim.
Brubakk
A O
AO
Bergh
K
K
Videm
V
V
Ustad
A L
AL
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology*; D015824:Blood-Air Barrier / Q000187:drug effects*; D001812:Blood-Brain Barrier / Q000187:drug effects*; D001929:Brain Edema / Q000209:etiology / Q000517:prevention & control*; D002682:Chinchilla; D015936:Complement C5a / Q000037:antagonists & inhibitors* / Q000276:immunology; D003664:Decompression / Q000009:adverse effects*; D004618:Embolism, Air / Q000209:etiology; D005260:Female; D007958:Leukocyte Count / Q000187:drug effects; D008297:Male; D020556:Neutrophil Infiltration / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects; D011817:Rabbits
D000888:Antibodies, Anti-Idiotypic; D015936:Complement C5a