Clearances of plasma proteins from pulmonary vascular beds of adult dogs and pups

Ultrastructural immunoperoxidase demonstration of autologous albumin in the alveolar capillary membrane and in the alveolar lining material in normal rats.

“…This immunoelectron microscope study brings an ultrastructural morphological demonstration of the presence of plasma albumin in the alveolar wall. This agrees with and illustrates the results of authors who have stressed the lymphatic clearance of plasma proteins 'from the pulmonary vascular bed (1,2) or who have shown that radioactive albumin injected into the pulmonary circulation could be recovered in alveolar washings (3). However, the interstitial clearance pathway of albumin cannot be deduced from the present morphological study.…”

“…The permeability of the alveolar-capillary membrane to protein macromolecules has been previously investigated using biochemical or morphological methods. The former have provided consistent data demonstrating that normal transfer of plasma proteins takes place in the lung from the blood vessels to the lymph channels (1,2), probably through the interstitial space, and that albumin crosses the alveolar membrane in both directions, from the capillary to the alveolus (3) and from the alveolus to the capillary (4-6); moreover, several investigations have stressed the presence of serum proteins, particularly albumin, in surface-active alveolar lining material (7)(8)(9)(10). The morphological studies, using foreign tracers of different molecular weights (ferritin, mol wt 500,000, molecular diameter [md] 110 ,~ [11]; catalase, mol wt 240,000 [11]; hemoglobin, mol wt 64,500, md 60 /~ [12]; and horseradish peroxidase [HRP], tool wt 40,000, md 40 50 ,~ [11,13,14]), in-THE JOURNAL OF CELL BIOLOGY .…”

Pulmonary Extravascular Chloride Space and Albumin Content in Adult Dogs and Puppies

“…The purpose of the present study was to determine the volume and albumin content of pulmonary interstitial fluid in order to compare these data with the protein concentration of lung lymph. Measurements of lung lymph flow and protein content (4,17) reported previously suggest that the pulmonary capillaries are more permeable in immature than in mature animals. In order to determine whether comparable differences exist in pulmonary interstitial fluid volume and albumin content, the present experiments were carried out in adult dogs and in puppies.…”

Reticuloendothelial System Uptake of Infused ¹²⁵l-Trypsin in Newborn and Adult Rats

“…Several studies have demonstrated that clearance from the vascular space is signifi cantly increased in newborns compared to adult animals and is thought to be related to increased capillary permeability in the new borns [13,14], Therefore, the increased 125I plasma levels in the newborns (compared to adults) may underestimate the amount of 125I-trypsin that escapes liver uptake in the new born. In addition, the decline in newborn plasma radioactivity after 15 min may also be related to this increased permeability.…”