Related Experiment Videos
Relative resistance to methotrexate by proliferating normal rabbit epidermal cells in vitro
In Vitro
|May 1, 1981
Summary
Rabbit keratinocytes show resistance to methotrexate's anti-proliferative effects. While mitosis was minimally inhibited, DNA synthesis was dramatically reduced, suggesting inherent resistance in these normal cells.
Area of Science:
- Dermatology
- Cell Biology
- Pharmacology
Background:
- Primary cell cultures of normal rabbit epidermal cells (keratinocytes) were established without enzymatic methods.
- Six experiments were conducted using cells from six different rabbits.
Purpose of the Study:
- To investigate the effects of methotrexate (MTX) on rabbit keratinocyte proliferation and DNA synthesis.
- To determine if rabbit keratinocytes exhibit inherent resistance to MTX.
Main Methods:
- Establishing primary rabbit keratinocyte cultures.
- Exposing cells to varying concentrations of methotrexate (MTX) for 24 hours.
- Measuring cell proliferation via mitosis counts and DNA synthesis via [3H]deoxyuridine uptake.
Main Results:
- Low doses of MTX (1 microgram/ml) showed significant inhibition of mitosis in only one of six experiments.
- Higher MTX doses (100 micrograms/ml) significantly inhibited mitosis in only two of six experiments.
- MTX at 1 microgram/ml for 24 hours dramatically inhibited DNA synthesis by over 95%.
Conclusions:
- Rabbit keratinocytes demonstrate minimal inhibition of mitosis by MTX under tested conditions.
- A significant discrepancy exists between MTX's effect on mitosis and DNA synthesis in rabbit keratinocytes.
- Rabbit keratinocytes may possess inherent resistance to the anti-proliferative actions of methotrexate.