Cell Cycle Synchronization of Human Lymphoid Cells in Vitro by 2,3-Dihydro-1H-imidazo[1,2-b]pyrazole

Awtar Krishan, Kamla Dutt Paika, Emil Frei

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


2,3 Dihydro 1H imidazo[1,2 b]pyrazole (IMPY), a DNA synthesis inhibitory drug, reversibly arrests growth of human lymphoblasts in vitro. DNA distribution histograms of cultures exposed to 0.5 to 2.0 mM IMPY show accumulation of cells with G1 early S DNA content. On reincubation in fresh medium, cell cycle traverse is resumed by the blocked cells in a synchronized manner. Maximum incorporation of [H3]thymidine into DNA (174 to 220% of control) and labeling indexes (72 to 86%) are seen after 4 hr of incubation, and a major increase in cell number is seen between the 9th and 13th hr. DNA distribution histograms of cells reincubated in fresh medium (after double block), show an initial increase in the number of cells with S-G2-M DNA content and a corresponding decrease in the number of G1 early S cells. After 4 hr of reincubation, a gradual increase in the number of G1 early S cells was seen as the earlier blocked cells completed cell cycle traverse and mitosis. Cells exposed to 2.0 mM IMPY took approximately 2 hr longer to traverse than did cells exposed to 0.5 mM IMPY.

Original languageEnglish (US)
Pages (from-to)138-142
Number of pages5
JournalCancer Research
Issue number1
StatePublished - Jan 1976

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


Dive into the research topics of 'Cell Cycle Synchronization of Human Lymphoid Cells in Vitro by 2,3-Dihydro-1H-imidazo[1,2-b]pyrazole'. Together they form a unique fingerprint.

Cite this