Effects of aging on surfactant forms in rats

Ueda, Takashi; Cheng, Gang; Kuroki, Yoshio; Sano, Hiroaki; Sugiyama, Kumiya; Motojima, Seiji; Fukuda, Takeshi

doi:10.1183/09031936.00.15108000

Cited by 15 publications

(5 citation statements)

References 27 publications

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“…Comparison of middle‐aged to older dogs revealed a lower proportion of PS in the latter, but the functional consequences of this difference are not known. Conversely, in rats, saturated PC content decreased significantly from 1 day to 3 months of age and still decreased between 3 and 29 months 32 . Results from these 2 studies indicate that species‐related differences may exist in the effect of age on surfactant composition.…”

Section: Discussionmentioning

confidence: 76%

“…Surfactant changes associated with pulmonary maturation are well documented in neonates from a number of animal species, 28–30 including the horse 27 . However, only a few reports exist on age‐related changes occurring after the neonatal period 31–35 . In addition, the effect of bronchoalveolar lavage fluid (BALF) sample characteristics (eg, BALF recovery, cell count, and cytological profile) has not been investigated in the horse.…”

mentioning

confidence: 99%

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Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture

Christmann¹,

Hite²,

Witonsky³

et al. 2009

Veterinary Internal Medicne

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Background: Surfactant alterations are described in horses after exercise, anesthesia, and prolonged transport, in horses with recurrent airway obstruction, and in neonatal foals. The effect of horse age or bronchoalveolar lavage fluid (BALF) sample characteristics on surfactant is unknown.Objectives: To evaluate surfactant phospholipid composition and function in healthy horses, and to investigate the influence of age and BALF sample characteristics on surfactant.Animals: Seventeen healthy horses 6-25 years of age maintained on pasture year-round. Methods: BALF was collected by standard procedures and was assessed for recovery volume, nucleated cell count (NCC), and cytology. Cell-free BALF was separated into crude surfactant pellet (CSP) and surfactant supernatant (Supe) by ultracentrifugation. Phospholipid and protein content were determined from both fractions. CSP phospholipid composition was analyzed by high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of CSP was evaluated with a pulsating bubble surfactometer. Regression analysis was used to evaluate associations between age, BALF sample characteristics, and surfactant variables.Results: Results and conclusions were derived from 15 horses. Increasing age was associated with decreased phospholipid content in CSP but not Supe. Age did not affect protein content of CSP or Supe, or surfactant phospholipid composition or function. Age-related surfactant changes were unaffected by BALF recovery percentage, NCC, and cytological profile.Conclusions and Clinical Importance: Older horses have decreased surfactant phospholipid content, which might be because of age-related pulmonary changes. Surfactant composition is unaffected by BALF sample characteristics at a BALF recovery percentage of at least 50%.

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Section: Discussionmentioning

confidence: 76%

mentioning

confidence: 99%

Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture

Christmann¹,

Hite²,

Witonsky³

et al. 2009

Veterinary Internal Medicne

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“…Multiple forms of surfactant exists in the alveolar space, which can be separated into two major forms by differential centrifugation: functional large aggregates and nonfunctional small aggregates [92]. An interesting observation related to aging is that in the rat lung, there was an increase in the proportion of large aggregates and a decrease in the conversion rate from large to small aggregates in vitro [151]. These somewhat contradictory observations do not specifically indicate any major change in the surface tension properties of the lining fluid.…”

Section: Alveolar Lining Fluidmentioning

confidence: 97%

Biomechanics of the Aging Lung Parenchyma

Suki

Bartolák‐Suki

2014

Engineering Materials and Processes

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Aging is a process that affects cells, the extracellular matrix (ECM), tissues, and organs. The lung is the entry of oxygen into the body and any deterioration in its ability to take up and distribute oxygen uniformly in the parenchyma compromises the cardiovascular system and hence contributes to the aging of the organism. In this chapter, we provide an overview of the biochemical, structural, and biomechanical properties of the aging lung parenchyma. We also discuss several measurement techniques that are suitable to assess the biomechanical properties of the lung. Following a review of general constitutive relations used in lung biomechanics, we derive a specific multiscale constitutive equation for the lung tissue strip that allows us to partition the contributions of collagen, elastin, their volume fraction, and their interaction with the proteoglycan matrix. This model provides a better understanding of how airspace enlargement, local stiffening of ECM fibers and macroscopic lung compliance are related to each other. These constitutive relations have important implications for lung function during aging. Specifically, there is an increase in ECM stiffness due to cross-linking of collagen which influences cellular behavior at the microscale. Despite ECM stiffening, at the scale of thousands of alveoli, parenchymal stiffness may be near normal and lung compliance may even increase in the elderly due to the enlargement alveoli enabling relatively normal gas exchange in the absence of exercise. Finally, we discuss possible new research directions that may help better understand and reduce the risk of pulmonary diseases of old age.

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“…LA function. The LA fraction of the surfactant isolated from the lavages is principally responsible for the main part of biophysical surfactant activity (13,29). The ability of LA to maintain airway patency was significantly reduced in children with chronic airway inflammation compared with controls.…”

Section: Discussionmentioning

confidence: 99%

Surfactant function in children with chronic airway inflammation

Braun

Steinecker²,

Schumacher³

et al. 2004

Journal of Applied Physiology

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Pulmonary surfactant is necessary to keep the terminal conducting airways patent. It is unknown whether mild to moderate airway inflammation may influence surfactant function and thus contribute to the pathogenesis of chronic airway inflammation in children. To answer this question, 21 children with chronic obstructive bronchitis and 19 asymptomatic children with long-term tracheostomy and increased numbers of neutrophils in their airways were compared with 15 healthy controls. Bronchoalveolar lavage fluid was separated into large surfactant aggregates (LA) and a supernatant containing inhibitory constituents. Surfactant function of LA, recombinations of LA and supernatant, and recombinations of a defined bovine surfactant and supernatant was assessed in a capillary surfactometer. Compared with controls, the function of the LA surfactant was reduced and there was no difference between children with tracheostomy and chronic obstructive bronchitis. The function of LA-supernatant recombinations was poor in all subjects. This may be explained by the well-known protein influx during the lavage procedure. The activity of bovine surfactant-supernatant reconstitutions was impaired in children with tracheostomy. In all surfactant mixtures assessed, surfactant function was inversely correlated to the number of neutrophils in the lavage fluid. Chronic lower airway inflammation with mild or no clinical symptoms is associated with impaired surfactant function. The dysfunction may contribute to airflow restrictions frequently observed in these children.

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Effects of aging on surfactant forms in rats

Cited by 15 publications

References 27 publications

Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture

Influence of Age on Surfactant Isolated from Healthy Horses Maintained on Pasture

Biomechanics of the Aging Lung Parenchyma

Surfactant function in children with chronic airway inflammation

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