Effects of hyperthermia on binding, internalization, and degradation of epidermal growth factor. [/sup 125/I]
/sup 125/I-epidermal growth factor was used as a molecular probe to study the effects of hyperthermia and local anesthetics on cultured Rat-1 cells. Heating cells at 45/sup 0/C for times up to 1 h caused a continuous decrease in EGF binding. Scatchard analysis showed that the decreased binding resulted from a decrease in the affinity of the EGF receptors rather than from a decrease in receptor number. Exposure to 42/sup 0/C had no effect on degradation. We compared the effects of heat to those caused by the local anesthetics procaine the lidocaine, which have been shown to prevent EGF degradation. Because procaine and lidocaine have been shown by others to potentiate the killing effects of hyperthermia on tumors and in cultured cells, we suggest that hyperthermia and the local anesthetics may act at the same cellular site. By inhibiting the action of lysosomes, hyperthermia and local anesthetics may permit potentially toxic materials to enter the cell by endocytosis, where they would accumulate and induce lethal damage.
- Research Organization:
- Univ. of Arizona Center for the Health Sciences, Tucson
- OSTI ID:
- 6568643
- Journal Information:
- Radiat. Res.; (United States), Vol. 86:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANESTHETICS
BIOLOGICAL EFFECTS
SYNERGISM
HYPERTHERMIA
PROCAINE
PROTEINS
MEMBRANE TRANSPORT
RECEPTORS
AMINES
DECOMPOSITION
FIBROBLASTS
GROWTH
IODINE 125
LYSOSOMES
PHAGOCYTOSIS
RATS
TOXIC MATERIALS
TRACER TECHNIQUES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BODY TEMPERATURE
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
RADIOISOTOPES
RODENTS
SOMATIC CELLS
VERTEBRATES
560201* - Thermal Effects- Cells- (-1987)