1. Tacrolimus and sirolimus are potent immunosuppressors used in transplantation. Tacrolimus has been suspected to alter mitochondrial respiration of different tissues but sirolimus has not been evaluated. 2. We evaluated the in vitro effect of tacrolimus and sirolimus on oxidative phosphorylation of isolated rat kidney mitochondria. 3. Oxygen consumption was measured with a Clark-type electrode. Tacrolimus and sirolimus increased the resting rate (state 4) and had no significant effect on ADP-stimulated respiration (state 3). The decrease of respiratory control ratio was concentration-dependent with a biphasic curve for tacrolimus. The EC(50)s were 3.4 x 10(-11) M and 2.3 x 10(-8) M for tacrolimus and 4.4 x 10(-10) M for sirolimus. The maximal inhibition was 20 and 14% for tacrolimus and sirolimus, respectively. 4. Tacrolimus and sirolimus had an uncoupling effect on oxidative phosphorylation related to a decrease of the inner membrane fluidity. At the opposite of cyclosporin A, no effect on swelling or Ca(2+) fluxes was observed. 5. All events occurred at therapeutic concentrations and then could appear during long-term treatment. Cellular consequences such as chronic nephrotoxicity with tacrolimus are suggested. The risk of cyclosporin A nephrotoxicity potentiation by sirolimus is discussed.
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http://dx.doi.org/10.1038/sj.bjp.0705038 | DOI Listing |
Iran J Pharm Res
September 2024
Department of Clinical Pharmacy and Pharmacy Practice, Isfahan University of Medical Sciences, Isfahan, Iran.
Background: Calcineurin inhibitors and mammalian target of rapamycin (mTOR) inhibitors are essential for maintaining transplanted organs. However, determining the appropriate dosage and predicting blood concentrations of these drugs based solely on net body weight may be inadequate. Previous studies have presented contradictory results regarding the impact of obesity on drug concentrations and transplant success.
View Article and Find Full Text PDFCell Transplant
January 2025
Department of Translational Research & Cellular Therapeutics, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope, Duarte, CA, USA.
Herein, we characterized the percentage of tacrolimus to the combined sirolimus and tacrolimus trough levels (tacrolimus %) observed during islet transplant-associated immune suppression therapy with post-transplant skin cancer. Although trough levels of tacrolimus and sirolimus were not different ( = 0.79, 0.
View Article and Find Full Text PDFJ Pharm Biomed Anal
December 2024
Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, the Netherlands; Leiden Network for Personalized Medicine, Leiden, the Netherlands. Electronic address:
Voclosporin is a potent immunosuppressive agent currently approved for treating active lupus nephritis. Based on its potential antiviral activity, it has also been investigated as immunosuppressive agent in an investigator-initiated study in SARS-CoV2 positive kidney transplant recipients. As with many immunosuppressive agents, optimizing dosing regimens to achieve therapeutic efficacy while minimizing toxicity remains a critical challenge in clinical practice.
View Article and Find Full Text PDFGenes Cells
January 2025
Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashiosaka, Japan.
Aggregation of alpha-synuclein (α-Syn) is implicated in the pathogenesis of several neurodegenerative disorders, such as Parkinson's disease and Dementia with Lewy bodies, collectively termed synucleinopathies. Thus, tremendous efforts are being made to develop strategies to prevent or inhibit α-Syn aggregation. Here, we genetically engineered fission yeast to express human α-Syn C-terminally fused to green fluorescent protein (GFP) at low and high levels.
View Article and Find Full Text PDFClin Transplant
December 2024
Department of Surgery, IU Health/Indiana University School of Medicine, Indianapolis, Indiana, USA.
This single-center retrospective study was designed to evaluate the use of basiliximab as an alternative rescue maintenance immunosuppression in situations where standard maintenance immunosuppression is not tolerated after a pancreas transplant. All pancreas transplants performed between January 11, 2006, and January 6, 2022, were reviewed. All recipients received rabbit antithymocyte globulin (rATG) induction with tacrolimus + sirolimus maintenance for simultaneous pancreas and kidney (SPK) and additional low-dose mycophenolic acid for pancreas transplant alone (PTA).
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