Influence of sildenafil and tadalafil on the enzyme- and transporter-inducing effects of bosentan and ambrisentan in LS180 cells
The combinations of the endothelin-1 receptor antagonists bosentan or ambrisentan with the phosphodiesterase 5 inhibitors sildenafil or tadalafil are current standard therapies of advanced pulmonary arterial hypertension. However, these drugs have a number of drug interactions. Changes of bosentan p...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
2013
|
| In: |
Biochemical pharmacology
Year: 2013, Volume: 85, Issue: 2, Pages: 265-273 |
| ISSN: | 1873-2968 |
| DOI: | 10.1016/j.bcp.2012.11.020 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1016/j.bcp.2012.11.020 Verlag, Volltext: http://www.sciencedirect.com/science/article/pii/S0006295212007617 
|
| Author Notes: | Johanna Weiss, Dirk Theile, Adriana Spalwisz, Jürgen Burhenne, Klaus-Dieter Riedel, Walter Emil Haefeli |
| Summary: | The combinations of the endothelin-1 receptor antagonists bosentan or ambrisentan with the phosphodiesterase 5 inhibitors sildenafil or tadalafil are current standard therapies of advanced pulmonary arterial hypertension. However, these drugs have a number of drug interactions. Changes of bosentan pharmacokinetics by sildenafil are attributed to reduced hepatic uptake as a consequence of inhibition of organic anion transporting polypeptides. We therefore tested in vitro the hypothesis that sildenafil and tadalafil reduce the enzyme- and transporter-inducing effects of bosentan or ambrisentan by preventing cellular access. Although intracellular concentrations of bosentan and ambrisentan (measured by high pressure liquid chromatography coupled with tandem mass-spectrometry) after four days of incubation of LS180 cells were lower when sildenafil or tadalafil were present, quantification of mRNA expression in these cells by real-time reverse transcription polymerase chain reaction revealed that bosentan and ambrisentan-mediated induction was stable or even increased in combination with sildenafil or tadalafil. For the drug transporter P-glycoprotein this was confirmed at the protein and functional level with highly significant correlations between P-gp mRNA, protein, and function. Moreover, using a reporter gene assay in LS180 cells, our study demonstrates for the first time that tadalafil is a potent, ambrisentan a weak, and sildenafil no activator of pregnane X receptor. In conclusion, our study demonstrates that although sildenafil and tadalafil indeed reduce intracellular concentrations of bosentan and ambrisentan in LS180 cells, they do not mitigate the inducing effects of these endothelin-1 receptor antagonists. |
|---|---|
| Item Description: | Available online 5 December 2012 Gesehen am 09.05.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1873-2968 |
| DOI: | 10.1016/j.bcp.2012.11.020 |