Clearance of surfactant protein B from rabbit lungs

To characterize the metabolism of surfactant protein B (SP-B) in vivo, we measured the clearance of SP-B from adult rabbit lungs. Purified rabbit SP-B was radiolabeled with 125I by the Bolton-Hunter method. Trace amounts of 125I-labeled SP-B mixed with [14C]dipalmitoylphosphatidylcholine (DPPC) were given intratracheally via a bronchoscope to rabbits 0-16 h before collection of alveolar washes (AW). Macrophages were recovered from AW, and lamellar bodies (LB) were isolated from lung tissue by differential centrifugation. 125I-SP-B was cleared more rapidly from the airspaces and the total lung (half-life 7 h) than was DPPC (half-life 11 h in the total lung). There was an approximately threefold accumulation of SP-B relative to saturated phosphatidylcholine in macrophages at all times. The proportion of 125I and 14C radioactivities in lamellar bodies was similar at 2 and 4 h, but there was 14-fold less 125I-SP-B than [14C]DPPC in lamellar bodies by 16 h. This loss of SP-B from the lamellar body fraction is consistent with less recycling of SP-B. The results demonstrate different clearance kinetics of these two components of surfactant and indicate a significant role of macrophages in the clearance of SP-B.

Download Full-text

The pathogenic role of surfactant protein B in formation of bronchopulmonary pathology in children

SOVREMENNAYA PEDIATRIYA ◽

10.15574/sp.2017.84.66 ◽

2017 ◽

pp. 66-71

Author(s):

O. Yablon ◽

◽

N. Zaichko ◽

O. Mazulov ◽

Z.I. Rossokha ◽

...

Keyword(s):

Surfactant Protein ◽

Pathogenic Role ◽

Surfactant Protein B ◽

Protein B

Download Full-text

Role of the N-Terminal Seven Residues of Surfactant Protein B (SP-B)

PLoS ONE ◽

10.1371/journal.pone.0072821 ◽

2013 ◽

Vol 8 (9) ◽

pp. e72821 ◽

Cited By ~ 7

Author(s):

Mahzad Sharifahmadian ◽

Muzaddid Sarker ◽

Dharamaraju Palleboina ◽

Alan J. Waring ◽

Frans J. Walther ◽

...

Keyword(s):

Surfactant Protein ◽

Surfactant Protein B ◽

Protein B

Download Full-text

The Use of Membrane Fusion to Understand the Role of Lung Surfactant Protein B in Lipid Trafficking

Biophysical Journal ◽

10.1016/j.bpj.2016.11.2115 ◽

2017 ◽

Vol 112 (3) ◽

pp. 389a

Author(s):

Kayla Kroning ◽

Otonye Braide

Keyword(s):

Membrane Fusion ◽

Lung Surfactant ◽

Surfactant Protein ◽

Lipid Trafficking ◽

Surfactant Protein B ◽

Lung Surfactant Protein ◽

Protein B

Download Full-text

Surfactant protein A metabolism in preterm ventilated lambs

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1992.262.6.l765 ◽

1992 ◽

Vol 262 (6) ◽

pp. L765-L772 ◽

Cited By ~ 6

Author(s):

M. Ikegami ◽

J. F. Lewis ◽

B. Tabor ◽

E. D. Rider ◽

A. H. Jobe

Keyword(s):

Gestational Age ◽

Protein A ◽

Lamellar Body ◽

Surfactant Protein ◽

Surfactant Protein A ◽

Lamellar Bodies ◽

Specific Activities ◽

Kinetics Of

Surfactant protein A (SP-A) metabolism was studied in vivo in 33 preterm ventilated lambs at 138 +/- 1 days gestational age by measuring recoveries of exogenously administered surfactant containing both radiolabeled SP-A and labeled saturated phosphatidylcholine (Sat PC) given via the trachea at birth. Endogenously secreted SP-A was also labeled with [35S]methionine and followed over 24 h. The exogenously labeled SP-A left the alveolar pool more rapidly than did Sat PC over the first 5 h of life (P less than 0.05), and both exogenously labeled SP-A and Sat PC were detected within lamellar bodies by 2 h, indicating uptake from the airspaces. The quantity of SP-A in alveolar washes increased about twofold from birth to 5 h of age, whereas alveolar Sat PC pools were constant over 24 h. The SP-A endogenously labeled with [35S]methionine was recovered at highest specific activities in the alveolar washes at 10 and 45 min after birth with no labeled SP-A detectable in lamellar body fractions until 2 h. The curve for endogenous SP-A labeling of lamellar bodies was similar to that for exogenous labeling, indicating that SP-A was initially secreted by a pathway independent of lamellar bodies with subsequent SP-A labeling of lamellar bodies. The kinetics of SP-A metabolism were very different than for Sat PC in preterm lambs.

Download Full-text

Surfactant protein A is localized at the corners of the pulmonary tubular myelin lattice.

Journal of Histochemistry & Cytochemistry ◽

10.1177/39.10.1940306 ◽

1991 ◽

Vol 39 (10) ◽

pp. 1331-1336 ◽

Cited By ~ 76

Author(s):

W F Voorhout ◽

T Veenendaal ◽

H P Haagsman ◽

A J Verkleij ◽

L M van Golde ◽

...

Keyword(s):

Protein A ◽

Surfactant Protein ◽

Surfactant Protein A ◽

Alveolar Type ◽

Type Ii ◽

Rat Lung ◽

Lamellar Bodies ◽

20 Nm

Immunogold labeling on sections of a freeze-substituted tubular myelin-enriched fraction isolated from a bronchoalveolar lavage of rat lung showed that surfactant protein A (SP-A) occurs predominantly at the corners of the tubular myelin lattice. Seventy-nine percent of the gold particles were located within 20 nm from a corner. Extracellular SP-A was detected only in the tubular myelin lattice and not in vesicles or secreted lamellar bodies. Ultra-thin cryosections of rat lung fixed in vivo showed that intracellular SP-A was distributed homogeneously over the stacked membranes of lamellar bodies in alveolar Type II cells. The presence of SP-A at the corners of the tubular myelin lattice suggests an important role of this protein in the formation and/or maintenance of this highly ordered lattice.

Download Full-text