Effects of various forms of surfactant protein C on tidal volume in ventilated immature newborn rabbits.
Surfactant protein (SP)-C is characterized by alpha-helix structure and palmitoyl groups attached to two cysteine residues. We examined the function of palmitoylation and dimerization in promotion of tidal volume in immature newborn rabbits. Reconstituted surfactants were made from a mixture of synthetic phospholipids and porcine SP-B (basic mixture) by adding various forms of SP-Cs: normal SP-C isolated from porcine lungs and monomeric or dimeric forms of SP-C. These latter two were isolated from patients with pulmonary alveolar proteinosis and were less palmitoylated. Animals were ventilated at an inspiratory pressure of 25 cmH2O. Median tidal volumes were <2 ml/kg in nontreated controls, 7.7 ml/kg in animals receiving the basic mixture without SP-C, and >18 ml/kg in animals treated with reconstituted surfactants containing 3% normal or 2% dimeric SP-C (P < 0.05 vs. basic mixture). The physiological effect of basic mixture was not improved by monomeric SP-C. We conclude that palmitoyl groups are important for the physiological effects of SP-C and that the dimeric form also improves physiological effects.
Tashiro
Katsumi
K
Department of Anesthesiology and Intensive Care Medicine, Graduate School of Medicine, Kanazawa University, Kanazawa 920-8641, Japan. tashirk@anesth.m.kanazawa-u.ac.jp
Ohta
Keisuke
K
Cui
Xiaoguang
X
Nishizuka
Kazuo
K
Yamamoto
Ken
K
Konzaki
Tomoharu
T
Kobayashi
Tsutomu
T
Suzuki
Yasuhiro
Y
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D019281:Dimerization; D006801:Humans; D019308:Palmitic Acid / Q000378:metabolism; D017433:Protein Structure, Secondary; D037721:Pulmonary Surfactant-Associated Protein C / Q000737:chemistry / Q000494:pharmacology*; D011817:Rabbits; D013552:Swine; D013990:Tidal Volume / Q000187:drug effects*
D037721:Pulmonary Surfactant-Associated Protein C; D019308:Palmitic Acid