Bronchoalveolar lavage fluid from normal rats stimulates DNA synthesis in rat alveolar type II cells
Proliferation of alveolar type II cells after lung injury is important for the restoration of the alveolar epithelium. Bronchoalveolar lavage fluid (BALF) may represent an important source of growth factors for alveolar type II cells. To test this possibility, BALF fluid was collected from normal rats, concentrated 10-fold by Amicon filtration, and tested for its ability to stimulate DNA synthesis in rat alveolar type II cells in primary culture. BALF induced a dose-dependent increase in type II cell DNA synthesis resulting in a 6-fold increase in (3H)thymidine incorporation. Similar doses also stimulated (3H)thymidine incorporation into rat lung fibroblasts by 6- to 8-fold. Removal of pulmonary surface active material by centrifugation did not significantly reduce the stimulatory activity of BALF for type II cells. The stimulation of type II cell DNA synthesis by BALF was reduced by 100% after heating at 100 degrees C for 10 min, and by approximately 80% after reduction with dithiothreitol, and after trypsin treatment. Dialysis of BALF against 1 N acetic acid resulted in a 27% reduction in stimulatory activity. The effect of BALF in promoting type II cell DNA synthesis was more pronounced when tested in the presence of serum, although serum itself has very little effect on type II cell DNA synthesis. When BALF was tested in combination with other substances that stimulate type II cell DNA synthesis (cholera toxin, insulin, epidermal growth factor, and acidic fibroblast growth factor), additive effects or greater were observed. When BALF was chromatographed over Sephadex G150, the activity eluted with an apparent molecular weight of 100 kDa.
- Research Organization:
- National Jewish Center for Immunology and Respiratory Medicine, Denver, CO (USA)
- OSTI ID:
- 6324123
- Journal Information:
- Am. Rev. Respir. Dis.; (United States), Vol. 139:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spontaneously hypertensive rat vascular smooth muscle cells in culture exhibit increased growth and Na+/H+ exchange
Arginine vasopressin promotes growth of rat glomerular mesangial cells in culture
Related Subjects
FIBROBLASTS
DNA REPLICATION
GROWTH FACTORS
BIOLOGICAL FUNCTIONS
LUNGS
INJURIES
CELL PROLIFERATION
CHROMATOGRAPHY
DOSE-RESPONSE RELATIONSHIPS
EPITHELIUM
LAVAGE
RATS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
AZINES
BODY
CONNECTIVE TISSUE CELLS
FUNCTIONS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MITOGENS
NUCLEIC ACID REPLICATION
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PROTEINS
PYRIMIDINES
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
SEPARATION PROCESSES
SOMATIC CELLS
TISSUES
VERTEBRATES
550901* - Pathology- Tracer Techniques