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.
Horiuchi
K
K
Hospital, National Institute of Radiological Sciences, Chiba City, Japan.
Miyamoto
T
T
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