Related Experiment Videos
Fibrinogen clearance from the pulmonary interstitium.
Lymphology
|September 1, 1979
Summary
Radioactive fibrinogen injected into dog airways cleared into the interstitium and lymph. Lymphatic drainage from the right lower lobe primarily enters the thoracic duct, suggesting accessory lymphaticovenous connections.
Area of Science:
- Pulmonary Physiology
- Lymphatic System Dynamics
- Fibrinogen Metabolism
Background:
- Previous studies showed radiolabeled fibrinogen instilled in dog airways enters the interstitium.
- Understanding the clearance pathways of interstitial fibrinogen is crucial for lung health research.
Purpose of the Study:
- To analyze the interstitial clearance of radiolabeled human fibrinogen (125I-RIF) from the canine lung.
- To quantify lymphatic and plasma transport of interstitial 125I-RIF.
- To determine the pulmonary interstitial distribution volume of fibrinogen relative to albumin.
Main Methods:
- Instillation of 125I-human fibrinogen into the right lower lobe airway of intact dogs.
- Analysis of plasma and lymph (right lymphatic duct and thoracic duct) for 125I activity.
- Separation of 125I activity into clottable, trichloroacetic acid (TCA) insoluble, and TCA soluble components.
- Intravenous injection of 131I-human fibrinogen to assess plasma-lymph clottability changes.
Main Results:
- Clottable and TCA-insoluble 125-RIF appeared in lymph from both the right lymphatic duct (RD) and thoracic duct (TD) in consistent ratios.
- Lymphatic drainage from the right lower lobe favors the thoracic duct over the right lymphatic duct (1.4:1 ratio).
- Clottable 125-RIF was detected in plasma only when the RD was absent, suggesting lymphaticovenous communications.
- Interstitial fibrinogen clearance is primarily convective, with an estimated pulmonary interstitial distribution volume of 70% that of albumin.
- Non-dialyzable 125-RIF products adhered to erythrocytes and were degraded within the vascular compartment.
Conclusions:
- The study elucidates the lymphatic clearance pathways for fibrinogen from the pulmonary interstitium in dogs.
- Evidence supports the existence of accessory lymphaticovenous connections influencing fibrinogen transport.
- Fibrinogen clearance from the lung interstitium is largely convective, with a distribution volume similar to albumin.