Control of pulmonary surfactant secretion in adult California sea lions
Autor: | Sandra Orgeig, Natalie Foot, Daniel Paul Costa, Dirceu Costa, Christopher Daniels |
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Přispěvatelé: | Orgeig, Sandra, Daniels, Christopher Brian, Miller, N, Costa, D |
Rok vydání: | 2004 |
Předmět: |
medicine.medical_specialty
Time Factors Zalophus californianus Cell Survival Diving Biophysics Biochemistry Pulmonary surfactant Internal medicine Pressure medicine Animals Secretion Respiratory system Sea lion Lung Molecular Biology Cells Cultured Sheep Alveolar type biology Ecology Respiration Pulmonary Surfactants Cell Biology biology.organism_classification Sea Lions Pulmonary Alveoli Endocrinology High pressure Hormone |
Zdroj: | Biochemical and Biophysical Research Communications. 313:727-732 |
ISSN: | 0006-291X |
Popis: | Marine mammals have a spectacular suite of respiratory adaptations to deal with the extreme pressures associated with deep diving. In particular, maintaining a functional pulmonary surfactant system at depth is critical for marine mammals to ensure that inspiration is possible upon re-emergence. Pulmonary surfactant is secreted from alveolar type II (ATII) cells and is crucial for normal lung function. It is not known whether ATII cells have the ability to continue to secrete pulmonary surfactant under pressure, or how secretion is maintained and controlled. We show here that surfactant secretion in California sea lions (Zalophus californianus) was increased after high pressures (25 and 50 atm) of short duration (30 min), but was unaffected by high pressures of long duration (2 h). This is in contrast to a similar sized terrestrial mammal (sheep), where surfactant secretion was increased after high pressures of both long and short duration. Z. californianus and terrestrial mammals also show similar responses to stimulatory hormones and autonomic neurotransmitters. It therefore seems that an increase in the quantity of surfactant in seal lungs after diving is most likely caused by mechanostimulation induced by pressure and volume changes, and that seals are adapted to maintain constant levels of surfactant under long periods of high pressure. |
Databáze: | OpenAIRE |
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