Effects of surfactant proteins SP-B and SP-C on dynamic and static mechanics of immature lungs.
To investigate the effects of surfactant proteins B (SP-B) and C (SP-C) on lung mechanics, we compared tidal and static lung volumes of immature rabbits anesthetized with pentobarbital sodium and given reconstituted test surfactants (RTS). With a series of RTS having various SP-B concentrations (0-0.7%) but a fixed SP-C concentration (1.4%), both the tidal volume with 25-cmH2O insufflation pressure and the static volume deflated to 5-cmH2O airway pressure increased, significantly correlating with the SP-B concentration: the former increased from 6.5 to 26.0 ml/kg (mean), and the latter increased from 6.4 to 31.8 ml/kg. With another series of RTS having a fixed SP-B concentration (0.7%) but various SP-C concentrations (0-1.4%), the tidal volume increased from 5.1 to 24.8 ml/kg, significantly correlating with the SP-C concentration, whereas the static volume increased from 3.4 to 32.0 ml/kg, the ceiling value, in the presence of a minimal concentration of SP-C (0. 18%). In conclusion, certain doses of SP-B and SP-C were indispensable for optimizing dynamic lung mechanics; the static mechanics, however, required significantly less SP-C.
Kobayashi
T
T
Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Kanazawa University, Kanazawa 920, Japan.
Tashiro
K
K
Yamamoto
K
K
Nitta
S
S
Ohmura
S
S
Suzuki
Y
Y
D000818:Animals; D000831:Animals, Newborn; D008168:Lung / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D011510:Proteolipids / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000502:physiology; D011663:Pulmonary Surfactants / Q000494:pharmacology*; D011817:Rabbits; D012121:Respiration, Artificial; D013552:Swine; D013990:Tidal Volume / Q000187:drug effects
D011510:Proteolipids; D011663:Pulmonary Surfactants