Effects of steroids and verapamil on P-glycoprotein ATPase activity: progesterone, desoxycorticosterone, corticosterone and verapamil are mutually non-exclusive modulators.

@article{Orlowski1996EffectsOS,
  title={Effects of steroids and verapamil on P-glycoprotein ATPase activity: progesterone, desoxycorticosterone, corticosterone and verapamil are mutually non-exclusive modulators.},
  author={St{\'e}phane Orlowski and Lluis M. Mir and Jean Belehradek and Manuel Garrigos},
  journal={The Biochemical journal},
  year={1996},
  volume={317 ( Pt 2)},
  pages={
          515-22
        }
}
P-glycoprotein (P-gp) is a membranous ATPase responsible for the multidrug resistance (MDR) phenotype. Using membrane vesicles prepared from the highly resistant cell line DC-3F/ADX we studied the influence of P-gp ATPase activity of four progesterone derivatives which specifically bind to P-gp and reverse MDR. Progesterone and desoxycorticosterone stimulate P-gp ATPase activity with, respectively, apparent concentrations giving half-maximal activation of 20-25 microM and 40-50 microM, and… 

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TLDR
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