Journal Article

Effect of 6 weeks of vitamin E administration on renal haemodynamic alterations following a single dose of neoral in healthy volunteers

Peter Bárány, Peter Stenvinkel, Astrid Ottosson‐Seeberger, Anders Alvestrand, Jason Morrow, J. Jackson Roberts and Abdulla K Salahudeen

in Nephrology Dialysis Transplantation

Published on behalf of European Renal Association - European Dialysis and Transplant Assoc

Volume 16, issue 3, pages 580-584
Published in print March 2001 | ISSN: 0931-0509
Published online March 2001 | e-ISSN: 1460-2385 | DOI: http://dx.doi.org/10.1093/ndt/16.3.580
Effect of 6 weeks of vitamin E administration on renal haemodynamic alterations following a single dose of neoral in healthy volunteers

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Background. A single oral dose of cyclosporin‐A (CsA) transiently reduces renal plasma flow (RPF) and glomerular filtration rate (GFR) in transplant patients and, in some patients, chronic administration of CsA leads to renal impairment and fibrosis. Based on experimental studies, several mediators including free radicals have been proposed to account for CsA‐nephrotoxicity. We have previously reported that administration of the antioxidant vitamin E in a rat model of chronic CsA‐nephrotoxicity reduces renal fibrosis and maintains renal function.

Methods. In the present study, the effect on renal haemodynamics of a single dose of the new oral formulation of CsA (neoral) was assessed before and after 6 weeks of vitamin E (800 IU/day, 2‐fold increase in serum vitamin E). GFR (inulin clearance) and RPF (para‐amino hippuric acid clearance) were measured before and after a single dose of 5 mg/kg of neoral in 12 healthy subjects under standardised conditions.

Results. Although the mean area under the curve of the CsA levels was 21% lower after the vitamin E period, the peak CsA level at 120 min after neoral was similar both before and after vitamin E administration. At 120 min after neoral, a transient reduction in RPF and GFR was noted both before and after vitamin E administration. The nadir of the reductions in RPF (−81±27 ml/min) and GFR (−14±6 ml/min) at 120 min compared with baseline tended to be lower before than after the treatment with vitamin E (−51±33 ml/min of RPF and −12±8,  ml/min of GFR, respectively). Plasma and urine levels of F2‐isoprostanes (free radical‐catalysed vasoconstrictive prostanoids (F2‐iso) at 120 min after the administration of neoral were not different from the pre‐neoral levels.

Conclusion. The findings demonstrate that a single oral dose of neoral causes transient, yet significant, reductions in RPF and GFR, and suggest that F2‐iso might not be involved in the CsA‐induced acute renal vasoconstriction. The tendency for a lower reduction in RPF and GFR following CsA during the vitamin E period in healthy humans warrants additional studies in transplant patients.

Keywords: cyclosporin A; glomerular filtration rate; renal plasma flow; vitamin E; tocopherol

Journal Article.  2730 words.  Illustrated.

Subjects: Nephrology

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