Int J Cancer  2003 Jan 1;103(1):138-41 

Potentiation of radiation-induced regrowth delay by isosorbide dinitrate in
FSaII murine tumors.

Jordan BF, Beghein N, Aubry M, Gregoire V, Gallez B.

Laboratory of Medicinal Chemistry and Radiopharmacy, Universite Catholique de
Louvain, Brussels, Belgium.

Oxygen deficiency in tumors reduces the efficacy of nonsurgical treatment
modalities such as conventional radiotherapy and chemotherapy. Since tumor
perfusion is directly affected by the vascular resistance to flow of vessels
feeding the tumor, vasodilator drugs might be a way to increase tumor blood flow
and oxygenation. The effects of nitric oxide (NO) donor administration on tumor
oxygenation, perfusion and radiation sensitivity were studied in the FSaII tumor
model. Local tumor oxygenation was measured using electron paramagnetic
resonance oximetry and a fiberoptic probe, OxyLite. We concomitantly measured
the modulation of tumor blood flow by laser Doppler flowmetry. We determined
FSaII tumor regrowth delay after isosorbide dinitrate administration and
irradiation compared to carbogen breathing before irradiation and with X-rays
alone. Administration of the NO donor improved the FSaII tumor pO(2) concomitant
with an increase in tumor blood flow. We also demonstrated an increase in FSaII
tumor radiation sensitivity after isosorbide dinitrate administration, which was
similar to the effect of carbogen breathing in the same tumor model.
Administration of isosorbide dinitrate could be considered in terms of
improvement in tumor blood flow and a possible concomitant increase in
accessibility of chemosensitizing agents to the tumor, particularly in terms of
modification of the tumor response to irradiation. Copyright 2002 Wiley-Liss,
Inc.

PMID: 12455068 [PubMed - indexed for MEDLINE]