In vivo demonstration of cell types in bone that harbor epidermal growth factor receptors
The binding and internalization of (/sup 125/I)iodoepidermal growth factor (EGF) by bone cells of the rat was demonstrated in situ by quantitative radioautography. Specific binding sites were observed on a cell profile enriched in endocytic components, including lysosome-like structures, a rough endoplasmic reticulum-rich cell profile, and a cell profile that histologically resembles an undifferentiated precursor cell. By the criteria of gel filtration and precipitability by trichloroacetic acid, most of the bound (/sup 125/I)iodo-EGF was considered intact. By morphological criteria none of the cell profiles that bound (/sup 125/I)iodo-EGF corresponded to fully formed osteoclasts or osteoblasts. The endocytic cell was found in the epiphyseal plate between the invading capillary and the transverse and longitudinal cartilage septa as well as near osteoclasts in the zone of mixed spicules. The rough endoplasmic reticulum-rich cell was present in vacated chondrocyte lacunae of the epiphyseal plate close to the metaphysis, and the poorly differentiated cell was observed between the mixed spicules of the metaphysis. Similar cell types were also found in the alveolar bone surrounding the incisors. These cells may be the origin of established bone cell lines that harbor high concentrations of EGF receptors and may also be responsible for the humoral hypercalcemia in response to the reported actions of injected EGF or transforming growth factor-alpha as well as that of malignancy.
- Research Organization:
- McGill Univ., Montreal, Quebec (Canada)
- OSTI ID:
- 6838481
- Journal Information:
- Endocrinology; (United States), Vol. 123:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Early ultrastructural changes in osteocytes from the proximal tibial metaphysis of mice after the incorporation of /sup 224/Ra
HISTOGENESIS OF Sr$sup 90$-INDUCED OSTEOSARCOMAS
Related Subjects
BONE CELLS
CELL DIFFERENTIATION
GROWTH FACTORS
RECEPTORS
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
ENDOPLASMIC RETICULUM
EPIDERMIS
FEMUR
IN VIVO
IODINE 125
LYSOSOMES
PRECIPITATION
RATS
STEM CELLS
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
EPITHELIUM
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MITOGENS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SEPARATION PROCESSES
SKELETON
SKIN
SOMATIC CELLS
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques