Changes in Sedimentation of Surfactant in Ventilated Excised Rat Lungs

Thet, Lyn A.; Clerch, Linda Biadasz; Massaro, Gloria D.; Massaro, Donald

doi:10.1172/jci109499

Cited by 70 publications

(11 citation statements)

References 24 publications

(21 reference statements)

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“…Although the properties and particularly the role of tubular myelin remains uncertain, there is evidence suggesting that it represents surface active material brought to an inactive state (33). A morphological study reveals continuity between tubular myelin and the concentric lamellae of the lamellar bodies (32).…”

Section: Discussionmentioning

confidence: 99%

Analysis of Labeling and Clearance of Lung Surfactant Phospholipids in Rabbit

Hallman¹,

Epstein²,

Gluck³

1981

J. Clin. Invest.

132

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A B S T R A C T Turnover and clearance of lung surfactant phospholipids were studied with particular reference to myoinositol-induced perturbation in the acidic phospholipids. Administration of myoinositol decreased [3H]palmitate and [32P]phosphate incorporation into phosphatidylglycerol by 80-90% in whole lung, and by 94-99% in lamellar bodies and in alveolar lavage. The increased incorporation of radioactive isotopes into phosphatidylinositol following myoinositol, was inverse to the decrease in phosphatidylglycerol incorporation. Myoinositol treatment affected neither content nor labeling of phosphatidylcholine or disaturated phosphatidylcholine as studied within 50 h of administration. Phosphatidylglycerol was pulse labeled by intravenous [32P]phosphate and [3H]-palmitate, followed by myoinositol. The biological half-lives of phosphatidylglycerol in the microsomal fraction, lamellar bodies, and alveolar lavage were 1.6, 4.6, 5.4 h (with 3H), and 2.8, 6.5, 7.0 h (with 32P), respectively.32P-labeled lung surfactant tracer was applied to the airways in saline suspension and the clearance of phospholipid radioactivity was measured in alveolar lavage, alveolar macrophages, lamellar bodies and lung homogenates. The clearance rates of phosphatidylcholine, disaturated phosphatidylcholine, phosphatidylglycerol, and phosphatidylinositol as studied in whole lung over 6 h were 3.4-5.8% h. Only a small amount of phospholipid radioactivity was recovered in the alveolar macrophage fraction (including bis-[monoacylglycerol]phosphate). Phospholipid radioactivity in alveolar lavage fell to 40-70% of the maximum during the 1st h, and to 5-18% over the next

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Section: Discussionmentioning

confidence: 99%

Analysis of Labeling and Clearance of Lung Surfactant Phospholipids in Rabbit

Hallman¹,

Epstein²,

Gluck³

1981

J. Clin. Invest.

132

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“…Experimental evidence in favor of this hypothesis was first provided by Thet et al [33], who demonstrated that in the excised rat lung ventilated for 2 h at constant tidal volume, areas of atelectasis could be removed by a single deep breath. Wirtz and Dobbs [34] confirmed many years later that a single distension of type II cells grown on silastic membranes stimulates surfactant secretion.…”

Section: Surfactant Secretion and Its Relation To Lung Distensionmentioning

confidence: 99%

Pulmonary Consequences of a Deep Breath Revisited

et al. 2004

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About two decades ago, a model was proposed for surfactant release by lung distension. This model implies rapid fusion of lamellar bodies (LBs) with the plasma membrane followed by quick release of surfactant into the alveolus, as reflected by immediate facilitation of lung inflation after a single deep breath. Recent experimental evidence indicates that this two-pool model (intracellular versus alveolar surfactant pool) has to be refined by introducing a third pool, which resides in fused but non-released LBs. Here we discuss the implication of this additional pool for strain-induced surfactant secretion and propose a revised model for the sequence of events following a single deep breath.

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“…The Annual Meeting of the European Society for Pediatric Research will be held in Padova, Italy, September [6][7][8][9][10]1987 …”

Section: Annual Meetingmentioning

confidence: 99%

“…The lavage samples were spun we chose to study this animal model because of the predictability in increasing centrifugal force fields, according to the expansion of its gestational age and because of the relatively immature state of the technique of Thet et al (9) given by Magoon, et 01. (10) of the newborn rat lung.…”

mentioning

confidence: 99%

Alterations of Surfactant Pools in Fetal and Newborn Rat Lungs

1987

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ABSTRACT. Preparation by the developing alveolar epithelium for the transition to air breathing and surfactant secretion at birth are critical components of neonatal survival. We combined morphometric analysis and biochemical assays of lung phospholipids to measure the amount and redistribution of lung surfactant during the perinatal period of rats. Within 10 min of the start of air breathing, there was a small increase in type I1 cell lamellar body content by morphometric and biochemical estimates. By 24 h, the whole lung and alveolar extracellular pool surfactant lipid had substantially increased. Subfractionation of the alveolar surfactant pool obtained at four times, from birth to 24 h of life, demonstrated a 20-fold increase in the ratio of phospholipid in a tubular myelin-rich fraction compared to a unilamellar vesicle-rich fraction. We conclude that packaging of surfactant may be very active immediately postbirth. Our results also indicate a major shift in the physical forms of extracellular surfactant during the first hours of air breathing. (Pediatr Res 21: 5-9, 1987) Abbreviations quantifying changes in the intracellular and extracellular pools of surfactant-associated phospholipid in the late fetal and newborn period, using morphometric and biochemical assays. METHODS Animals.Timed pregnant (previously virgin) Sprague-Dawley females (Zivic-Miller, Allison Park, PA) were received 5 to 7 days prior to parturition. During their late stages of pregnancy, they were allowed food and water ad libitum and were kept in 12-h light-dark cycles. The onset of labor was defined as behavior including nest building and agitation along with vaginal bleeding. Birth began shortly after nesting was complete and was allowed to progress uninterrupted until three to six fetuses were delivered. The air-breathing newborns were kept with the unanesthetized mother. The mothers were then anesthetized with 30-50 mg/kg pentobarbital intraperitoneally; the remaining fetuses were delivered individually through a hysterotomy. These fetuses (birth group) were more lethargic, but made limb motions. They were still connected to the placenta and made no respiratory efforts. The mothers continued spontaneous breathing during the entire procedure. DSPC, disaturated phosphatidylcholineNo more than 10 min passed before the newborns (+lo min PL, phospholipid group) were also anesthetized with intraperitoneal pentobarbital, LDH, lactate dehydrogenase the thoracic contents were rapidly removed and lung wet weight was obtained. Two or three unlavaged lungs were pooled for the LB DSPC' lamellar body disaturated phosphatidylcholine ~h o s~h o l i p i d determinations in all fetal animals. Pooled s a m~l e s -A -from these animals were regarded as a single determination. Since the +10 min group were expected to have developed in the lower poles of the uterus, we obtained lungs from fetuses in Immediately after birth, the newborn must transition to air the two lowest and the two highest uterine positions of four breathing and the effects this has on...

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Changes in Sedimentation of Surfactant in Ventilated Excised Rat Lungs

Cited by 70 publications

References 24 publications

Analysis of Labeling and Clearance of Lung Surfactant Phospholipids in Rabbit

Analysis of Labeling and Clearance of Lung Surfactant Phospholipids in Rabbit

Pulmonary Consequences of a Deep Breath Revisited

Alterations of Surfactant Pools in Fetal and Newborn Rat Lungs

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