tacrolimus and aliskiren

Tacrolimus (Tac) and Cyclosporine A (CyA) calcineurin inhibitors (CNIs) are 2 effective immunosuppressants which are essential to prevent allograft rejection. Calcineurin inhibitors are known to be nephrotoxic. However, the precise mechanism of nephrotoxicity is not fully understood. In this study, we investigated the in vivo effects of CNIs on the local renal renin-angiotensin system in the collecting duct (CD).. Three-week-old mice were treated with either vehicle, CyA (2 mg/kg per day), Tac (0.075 mg/kg per day), CyA + Aliskiren (25 mg/kg per day), or Tac + Aliskiren for 3 weeks. Serum creatinine was measured. Renin and vascular endothelial growth factor (VEGF) contents in CD were evaluated with flow cytometry and multiphoton microscopy. The diameter of vessels was assessed with multiphoton microscopy, and the amount of renal collagen was determined by real-time polymerase chain reaction and Masson staining.. The elevated level of serum creatinine in CNI groups was abolished by Aliskiren. Flow cytometric analysis found elevated renin content in principal cells, which was prevented by Aliskiren. This result was further confirmed with multiphoton microscopy. The VEGF content in CD correlated with reduced capillary diameter and with the formation of fibrotic islands.. Calcineurin inhibitors induce production of renin in the CD that may contribute to decreased renal blood flow. In turn, CD responds with increased VEGF production, resulting in disproportional vessel growth, further worsening the local hypoxia and striped fibrosis surrounding the CDs. Aliskiren, a direct renin inhibitor blocks these effects and improves CNI-induced nephropathy by decreasing renin production in the CDs. Our data suggest that Aliskiren may be used for the prevention of CNI nephrotoxicity.

Topics: Amides; Animals; Biomarkers; Calcineurin Inhibitors; Capillaries; Collagen Type I; Creatinine; Cyclosporine; Cytoprotection; Disease Models, Animal; Fibrosis; Flow Cytometry; Fumarates; Immunosuppressive Agents; Kidney Diseases; Kidney Tubules, Collecting; Male; Mice, Inbred C57BL; Microscopy, Fluorescence, Multiphoton; Real-Time Polymerase Chain Reaction; Renal Circulation; Renin; Renin-Angiotensin System; Tacrolimus; Time Factors; Up-Regulation; Vascular Endothelial Growth Factor A

Tacrolimus is frequently used as immunosuppressive agent in organ transplantation but its clinical use is limited due to its marked nephrotoxicity.. Male Wistar albino rats weighing 150-200 g (10-12 weeks old) were used. Animals were divided into four groups. Group 1 served as control group and received normal saline, group 2 served as toxic group and received 2 mg/kg tacrolimus i.p., group 3 served as treatment group and received 2 mg/kg tacrolimus i.p. followed by 2 mg/kg aliskiren orally and group 4 served as drug per se group and received 2 mg/kg aliskiren orally. Tacrolimus-induced nephrotoxicity was assessed biochemically and histopathologically.. Treatment with aliskiren decreased the tacrolimus-induced changes in biochemical markers of nephrotoxicity such as blood urea nitrogen and creatinine. Aliskiren also attenuated the effects of tacrolimus on oxidative stress parameters such as malondialdehyde, reduced glutathione and catalase. Histopathological and ultrastructural studies showed that aliskiren attenuated tacrolimus-induced renal damage.. These results suggest that aliskiren has protective effects against tacrolimus-induced nephrotoxicity; implying that renin inhibitor may counteract nephrotic syndrome associated with immunosuppressant use.

Topics: Amides; Animals; Catalase; Fumarates; Glutathione; Kidney; Kidney Diseases; Lipid Peroxidation; Male; Oxidative Stress; Rats, Wistar; Tacrolimus

Tacrolimus (TAC), a calcineurin inhibitor, is commonly used as an immunosuppressive agent in organ transplantation, but its clinical use may be limited due to cardiotoxicity. Olmesartan (OLM; angiotensin receptor blocker) and aliskiren (ALK; renin inhibitor) may attenuate cardiotoxicity induced by TAC by inhibition of renin-angiotensin aldosterone system.. The aim of this study was to evaluate the effect of OLM and ALK on TAC-induced cardiotoxicity.. Male Wistar albino rats weighing 200-250 g (10-12 weeks old) were used in this study. Animals were divided into four groups. Group 1 received normal saline, group 2 received TAC (2 mg/kg, intraperitoneally for 14 d), group 3 received OLM (2 mg/kg, p.o. for 28 d) + TAC and group 4 received ALK (50 mg/kg, p.o. for 28 d) + TAC. TAC-induced cardiotoxicity was assessed biochemically and histopathologically.. Treatment with OLM or ALK decreased the TAC-induced changes in biochemical markers of cardiotoxicity such as serum aspartate transaminase, creatine kinase and lactate dehydrogenase. OLM or ALK also attenuated the effects of TAC on oxidant-antioxidant parameters such as malondialdehyde, reduced glutathione and catalase. Histopathological and ultrastructural studies showed that OLM or ALK also attenuated TAC-induced cardiotoxicity.. These results suggest that OLM as well as ALK has protective effects against TAC-induced cardiotoxicity; implying that angiotensin receptor blocker or renin inhibitor, respectively, may counteract cardiotoxicity associated with immunosuppressant use.

Topics: Amides; Animals; Fumarates; Heart; Imidazoles; Immunosuppressive Agents; Male; Myocardium; Rats; Rats, Wistar; Tacrolimus; Tetrazoles

Topics: Amides; Anemia; Antihypertensive Agents; Benzazepines; Drug Administration Schedule; Drug Approval; Drug Combinations; Drug Delivery Systems; Erythropoietin; Ferrosoferric Oxide; Fumarates; Humans; Hyponatremia; Immunosuppressive Agents; Kidney Diseases; Nanoparticles; Nephrology; Renal Dialysis; Renin; Tacrolimus; Tolvaptan