Radioreductive effect of bestatin (Ubenimex) in BALB/c mice.
The radioreductive effect of Bestatin (Ubenimex), a biological response modifier, was examined in BALB/c mice. Consecutive daily administrations from day 0 to day 3 after lethal irradiation resulted in a dose reduction factor (DRF) of 1.03. In haematological studies Bestatin enhanced the recovery of peripheral leucocytes in sublethally irradiated mice by activating colony-stimulating factors (CSF) in serum, leading to enhanced recovery of GM-CFC. There was no enhancement of CSF in BALB/c nude mice. On the other hand, Bestatin showed no effect on day 12 CFU-S and day 7 CFU-S after the sublethal irradiation, though there was a trend that the drug stimulated numbers of day 7 CFU-S after irradiation. These results strongly suggest that Bestatin enhanced the CSF activity by modulating T cell function, resulting in the augmentation of peripheral leucocytes and prolongation of survival of irradiated mice. This drug now used in the clinic proved to be modestly effective.
Hospital, National Institute of Radiological Sciences, Chiba City, Japan.
K
K
Horiuchi
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T
Miyamoto
D000208:Acute Disease; D000818:Animals; D007155:Immunologic Factors / Q000627:therapeutic use*; D007930:Leucine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011833:Radiation Injuries, Experimental / Q000188:drug therapy* / Q000517:prevention & control
D007155:Immunologic Factors; D007930:Leucine; C012211:ubenimex