Study on Reversal of Resistance to Homoharringtonnine (HH) by Calcium Antagonist in DBA/2 Mouse Transplantable L₁₂₁₀ Leukemia Cells

HH-resistant DBA/2 mouse L₁₂₁₀(L₁₂₁₀) leukemia modal was established in our laboratory. Calcium antagonists were used to reverse HH resistance of these sublines. The results showed that the servival of mice was prolonged and HH resistance of L₁₂₁₀/HR cells was reversed by verapamil. The concentrations of verapamil and nitrendipine in L₁₂₁₀/HR cells were also measured. After L₁₂₁₀/HR cells reversed by verapamil, the amount of HH was markedly accumulated in L₁₂₁₀/HR sublines.