0000000000329374
AUTHOR
Hamao Umezawa
Synergistic effect of peplomycin in combination with bleomycin on L5178y mouse lymphoma cells in vivo.
Studying the treatment of NMRI mice with ip injections of bleomycin (BLM) for 5 days we found an approximate LD50 of 35 mg/kg; the toxicity of peplomycin (PEP) was slightly higher (LD50: approximately 25 mg/kg). The effect of the two drugs on growth of L5178y mouse lymphoma cells in NMRI mice was examined. BLM alone caused at a concentration of 2.5 mg/kg an almost complete inhibition of tumor cell growth; the same effect was determined with 1 mg PEP/kg. At these concentrations the drugs caused an increase of the survival time of 110% (BLM) or 104% (PEP). Given in combination, one-sixth of the optimal doses yielded an 100% increase of the median survival time. These results indicate a signif…
The role of bestatin, an inhibitor of cell surface proteases, in the interaction of serum with untransformed cells in culture.
Bestatin is an inhibitor of cell surface-associated aminopeptidase B and leucine aminopeptidase. This microbial product simulates the role of serum as an activator of uridine uptake in quiescent BHK cells. The compound significantly stimulates the incorporation of labelled thymidine into the acid-insoluble fraction of serum-starved Nil 8 cells in the presence of low concentration of serum. The possible mechanisms of these interactions are discussed.