Enhanced lysis of (/sup 125/I)5-iodo-2'-deoxyuridine-labeled target cells in the presence of normal macrophages: possible mechanisms of action

Journal Article · Tue Jan 01 04:00:00 EST 1985 · J. of Leukocyte. Biol.; (United States)

OSTI ID:5726712

Evans, R; Eidlen, D M

The potential mechanisms involved during the faster release of (/sup 125/I)-iodo-2'-deoxyuridine (/sup 125/IdUrd)-labeled target sarcoma cells in the presence of normal C57BL/6J peritoneal macrophages were investigated. Maximum (. 90%) spontaneous release of /sup 125/I from target cells cultured alone occurred over a period of about 10 days. However, after about 3 days, confluent sheets of target cells developed. In the presence of normal macrophages, 90% of the /sup 125/I was released between 3 and 7 days, again with the formation of confluent sheets of target cells. This enhanced /sup 125/I release was not influenced by increasing the relative concentration of IdUrd using the nonradioactive isotope 127IdUrd. Established mechanisms of target cell destruction were investigated but no evidence was found for the involvement of superoxide anion, hydrogen peroxide, or regulation by prostaglandin synthesis. The macrophage-mediated effect was abrogated by incorporating hydrocortisone-acetate (10(-7) to 10(-4) M) into the culture medium but this did not affect target cell proliferation. The use of serum-free culture medium suggested that macrophages secreted a soluble mediator that was not derived from or dependent on the presence of fetal bovine serum. In addition, macrophage-conditioned medium was able to induce the faster /sup 125/I release. The failure to precipitate with 20% trichloroacetic acid the /sup 125/I released from target cells cultured in the presence of macrophages indicated that the radioactive component had been separated from the precipitable DNA. The data are discussed in light of two possible hypotheses: that macrophages recognized subtle changes in IdUrd-labeled cells and exacerbate radiotoxicity, and that the faster release reflected proliferative death caused by stimulated growth.

• Research Organization: Jackson Lab., Bar Harbor, ME
• OSTI ID: 5726712
• Journal Information: J. of Leukocyte. Biol.; (United States), Journal Name: J. of Leukocyte. Biol.; (United States) Vol. 37:1
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANTIMETABOLITES
AZINES
BETA DECAY RADIOISOTOPES
CELL CULTURES
CELL KILLING
CELL PROLIFERATION
CHEMICAL ACTIVATION
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DEOXYURIDINE
DISEASES
DNA REPLICATION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE 127
IODINE ISOTOPES
ISOTOPES
MACROPHAGES
NEOPLASMS
NUCLEI
NUCLEIC ACID REPLICATION
NUCLEOSIDES
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHAGOCYTES
PYRIMIDINES
RADIOISOTOPES
RIBOSIDES
SARCOMAS
SOMATIC CELLS
STABLE ISOTOPES
TUMOR CELLS
URACILS