Modulation of Human Plasma Fibronectin Levels Following Exercise,
Abstract
Tissue and plasma fibronectin (PF) represent two forms of this large molecular weight (440 kilodaltons) glycoprotein. While the tissue type is cell-associated and important to cell adhesion and shape, PF circulates in the blood and serves as a nonspecific opsonin for the reticuloendothelial system (RES). Although it may not participate in all forms of RES clearance. PF is an important contributor to this RES function. It supports particulate clearance by binding to material released to the vascular space as the result of tissue injury and thereby enhances the engulfment of this debris by the phagocytic cells of the RES. In this way, PF influences blood vessel patency and continued blood flow. Augmentation of particulate clearance by PF is perhaps one explanation for the correlation between elevated RES function and increased survival after shock. RES function and PF are suppressed after shock and trauma. Trauma-induced organ failure correlates with reduced PF level. While PF concentration rapidly recovers in survivors that have experienced traumatic episodes, it remains suppresses in nonsurvivors. Immunoglobulin reduction of PF results in decreased phagocytosis and decreased resistance to shock. Moreover, experimental rat heat stress mortality rate is significantly lessened by increased RES clearance capacity and naturally occurring elevations in PF level. Hence, elevation of PF may influence the outcome of trauma and correlate with the degree of tolerance to environmental stress. This study was undertaken to evaluate the potential of exercise as a means of increasing circulating PF concentration in human subjects.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA192674
Entities
People
- David A. Dubose
- L. E. Armstrong
- M. Lukason
- W. J. Kraemer
Organizations
- United States Army Research Institute of Environmental Medicine