MOZDARANI H, JADIDI M. THE INTERACTION OF RADIATION AND INTERCALATING AGENTS IN NORMAL BONE MARROW CELLS AS EVALUATED BY SPLEEN COLONY ASSAY TECHNIQUE: THE EFFECTS OF BLEOMYCIN SULFATE AND ACT INOMYCIND.. Med J Islam Repub Iran 1995; 9 (2) :137-145
URL:
http://mjiri.iums.ac.ir/article-1-1340-en.html
From the School of Medical Sciences, Tarbiat Modarres University. Tehran. Islamic Republic of Iran
Abstract: (5659 Views)
The relationship between the way in which normal hemopoietic stem
cells respond to irradiation alone or in the presence of bleomycin sulfate
(BLM-S) and actinomycin 0 (ACT-D) was investigated. Single doses of
BLM-S at 0.3 mg/kg and ACT-O at 0.10 mg/kg body weight were injected
intravenously 1-6 hours prior to whole body irradiation and treatment was
repeated twice more with time intervals. When assessed by survival of
spleen colony forming units (CFU-S) of bone marrow cells (BMC), BLM-S
alone caused only 10% reduction in survival compared to controls. There
was not a significant difference in survival fraction (SF) when treatment with
BLM-S was repeated twice more. On the other hand, ACT-O alone caused a
45% reduction in SF after the first injection and only a 10% reduction after
the third injection. Increase in survival might be due to resistance induced in
BMC after treatments with the drugs. The difference between the 'SF of
BMC of mice exposed to doses of 1-3 Gy whole body irradiation was statistically
significant with a p-value <0.05. When used in combination with
radiation, neither BLM-S nor ACT-O caused a synergistic or additive effect.
Although survival was seen to be lower for ACT-O treated animals, the
effect was not as pronounced as expected. A significant change in the results
was also not observed for fractionated doses of gamma rays in the presence
of BLM-S and ACT-O injected at various time intervals. Results obtained
from the administration of drugs at various time intervals before irradiation
does not suggest a specific time for drug treatment prior to irradiation. These
results also suggest that no potentiating effect is likely to be produced by a
combination of BLM-S or ACT-O and radiation therapy in bone marrow
cells. We therefore believe that these drugs induce a modest resistive response
to the effects of radiation on bone marrow cells by a mechanism
which is not yet understood. Therefore, using this agent repeatedly for cancer
treatment might not cause severe adverse biological effects in bone marrow
stem cells.