Probe for intracellular concentrations of drugs: delayed fluorescence from acridine orange
The aim of this work is to develop fluorescent probes that will indicate effective concentrations of therapeutic agents, or endogenous protectors, at important cellular sites. Acridine orange associates with nucleic acids and emits a 'delayed' fluorescence signal. This signal is quenched by oxidants such as oxygen, nitroaryl radiosensitizers, adriamycin and mitomycin-c, and reductants such as thiols, ascorbate and other radioprotectors. The quenching of the acridine orange delayed fluorescence reflects the effective concentration of these therapeutically-important oxidants and reductants near DNA. The relative concentration of basic radiosensitizers such as pimonidazole (Ro 03-8799) near the DNA is greater than that of misonidazole. Thiols quench the delayed fluorescence signal according to the degree of ionization of the thiol function; this may model the reactivity of thiols with guanine radical sites in DNA. Ascorbate and aminopyrine do not quench the delayed fluorescence from cells stained with acridine orange as these compounds are taken up by cells very inefficiently.
- Research Organization:
- Mount Vernon Hospital, Northwood (England)
- OSTI ID:
- 6253686
- Journal Information:
- Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 16:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACRIDINE ORANGE
FLUORESCENCE
RADIOSENSITIZERS
SUBCELLULAR DISTRIBUTION
ANTINEOPLASTIC DRUGS
DNA
IN VITRO
MITOMYCIN
OXYGEN
RADIOPROTECTIVE SUBSTANCES
THIOLS
ACRIDINES
AMINES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIMITOTIC DRUGS
AROMATICS
AZAARENES
AZINES
DISTRIBUTION
DRUGS
DYES
ELEMENTS
HETEROCYCLIC COMPOUNDS
LUMINESCENCE
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PYRIDINES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture