title: Effects of ventilation with different positive end-expiratory pressures on cytokine expression in the preterm lamb lung.
abstract: Ventilator-induced lung injury increases proinflammatory cytokines in the adult lung. We asked if positive end-expiratory pressure (PEEP) affects proinflammatory cytokine mRNA expression in the preterm lung. Preterm lambs at 129 +/- 3 d gestation were treated with 100 mg/kg recombinant human surfactant protein-C surfactant and ventilated for 2 or 7 h with 0, 4, or 7 cm H(2)O of PEEP. Unventilated fetal lambs were used as controls. Within 2 h of ventilation, alveolar total protein and activated neutrophils were increased and expression of mRNAs for the proinflammatory cytokines interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) was increased in lung tissue of all ventilated animals relative to unventilated controls. Alveolar protein and neutrophils were higher for 0 and 7 PEEP animals than 4 PEEP animals. IL-1beta, IL-6, and IL-8 mRNAs were significantly elevated in animals ventilated with 0 PEEP compared with 4 PEEP. The percentage fractional area of collapsed alveoli was significantly higher for 0 PEEP compared with 4 and 7 PEEP groups. Mechanical ventilation increased the expression of proinflammatory mediators in surfactant-treated preterm lungs and the use of 4 PEEP minimized this response.
authors.affiliation: Children's Hospital Medical Center, Division of Pulmonary Biology, Cincinnati, Ohio 45229, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Naik
authors.forename: S G
authors.initials: SG
authors.lastname: Kallapur
authors.forename: C J
authors.initials: CJ
authors.lastname: Bachurski
authors.forename: A H
authors.initials: AH
authors.lastname: Jobe
authors.forename: J
authors.initials: J
authors.lastname: Michna
authors.forename: B W
authors.initials: BW
authors.lastname: Kramer
authors.forename: M
authors.initials: M
authors.lastname: Ikegami
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D016207:Cytokines / Q000494:pharmacology*; D004195:Disease Models, Animal; D006801:Humans; D007231:Infant, Newborn; D007249:Inflammation; D007385:Intermittent Positive-Pressure Ventilation; D011650:Pulmonary Alveoli / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D011897:Random Allocation; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology*; D012756:Sheep; D013501:Surface-Active Agents
chemical_list: D016207:Cytokines; D012333:RNA, Messenger; D013501:Surface-Active Agents