Alterations in pulmonary surfactant after rapid arousal from torpor in the marsupial Sminthopsis crassicaudata

• Published in: Journal of applied physiology (1985) 1999-06, Vol.86 (6), p.1959-1970
• Main Authors: Lopatko, Olga V, Orgeig, Sandra, Palmer, David, Schurch, Samuel, Daniels, Christopher B
• Format: Article
• Language: English
• Subjects: Adsorption; Air breathing; Animals; Arousal - physiology; Biological and medical sciences; Body Temperature; Cholesterol - analysis; Chronobiology; Fundamental and applied biological sciences. Psychology; Hibernation - physiology; Lipids - analysis; Lungs; Male; Marsupialia - physiology; Marsupials; Phospholipids - analysis; Pulmonary Surfactants - chemistry; Pulmonary Surfactants - metabolism; Respiratory system; Respiratory system: anatomy, metabolism, gas exchange, ventilatory mechanics, respiratory hemodynamics; Surface Properties; Thermodynamics; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: respiratory system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1999.86.6.1959

1  Department of Physiology, The University of Adelaide, Adelaide, South Australia 5005; and 2  Respiratory Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1 Torpor in the dunnart, Sminthopsis crassicaudata , alters surfactant lipid composition and surface activity. Here we investigated changes in surfactant composition and surface activity over 1   h after rapid arousal from torpor (15-30°C at 1°C/min). We measured total phospholipid (PL), disaturated PL (DSP), and cholesterol (Chol) content of surfactant lavage and surface activity (measured at both 15 and 37°C in the captive bubble surfactometer). Immediately after arousal, Chol decreased (from 4.1 ± 0.05 to 2.8 ± 0.3 mg/g dry lung) and reached warm-active levels by 60 min after arousal. The Chol/DSP and Chol/PL ratios both decreased to warm-active levels 5 min after arousal because PL, DSP, and the DSP/PL ratio remained elevated over the 60 min after arousal. Minimal surface tension and film compressibility at 17 mN/m at 37°C both decreased 5 min after arousal, correlating with rapid changes in surfactant Chol. Therefore, changes in lipids matched changes in surface activity during the postarousal period. phospholipids; cholesterol; surface activity; surface tension; temperature