Surfactant treatment effects on lung structure and type II cells of preterm ventilated lambs

• Published in: Biology of the neonate Vol. 77; no. 4; pp. 243 - 252
• Main Authors: PINKERTON, K. E, IKEGAMI, M, DILLARD, L. M, JOBE, A. H
• Format: Journal Article
• Language: English
• Published: Basel Karger 01.01.2000; S. Karger AG
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Animals, Newborn - physiology; Biological and medical sciences; Emergency and intensive care: neonates and children. Prematurity. Sudden death; Gestational Age; Intensive care medicine; Lung - pathology; Medical sciences; Organelles - pathology; Pulmonary Alveoli - pathology; Pulmonary Surfactants - therapeutic use; Respiration, Artificial - adverse effects; Sheep; Premature; Lung disease; Alveolar type II cell; Exogenous; Animal model; Respiratory disease; Lamellar body; Lamb; Pathology; Newborn diseases; Vertebrata; Mammalia; Histopathology; Prematurity; Pulmonary surfactant; Newborn animal; Bronchus disease; Sheep; Bronchopulmonary dysplasia; Respiratory distress; Artiodactyla; Ungulata
• ISSN: 0006-3126; 1661-7800; 1421-9727; 1661-7819
• DOI: 10.1159/000014223

We evaluated surfactant treatment effects on lung morphology and alveolar type II cells of preterm ventilated lambs. Lambs were ventilated for 10 h following treatment of the right lung with natural surfactant. Lung parenchyma from the surfactant-treated right and the untreated left lung was compared morphometrically. Mechanical ventilation without surfactant resulted in distention of alveolar ducts accompanied by shallowing and loss of well-defined alveoli without disruption of collagen or elastin fibers. Surfactant treatment almost completely prevented these changes. The percent of normal parenchyma was 82 +/- 7% in surfactant-treated lobes and 26 +/- 5% in the nontreated lobes (p < 0.05). Type II cells became flatter in lungs ventilated without surfactant, and cell shape was preserved by surfactant treatment. The volume densities of lamellar bodies and multivesicular bodies in alveolar type II cells were not changed by surfactant treatment. With or without surfactant treatment, mechanical ventilation was associated with a shift in lamellar body distribution to a smaller size and a decrease in glycogen content of type II cells. Surfactant treatment of the preterm lung prevents alveolar distortion and atelectasis, but does not result in changes in subcellular organelles in immature type II cells.