L-carnitine and acetyl-L-carnitine status during hemodialysis with acetate in humans: a kinetic analysis.
The effects of the acetate content of hemodialysis fluids on the relation between L-carnitine (free carnitine, cr FC) and acetyl-L-carnitine (AC) have not previously been examined in detail. The net fluxes of FC, AC, and acetate between intra- and extracellular pools during hemodialysis were calculated using a kinetic model with dialysates containing three concentrations of FC (0, 40, and 80 mumol/L) and either 40 or 3 mmol acetate/L. Radioenzymatic assays of FC and AC were optimized for use with samples taken during hemodialysis. Acetate stimulated a tissue uptake of FC (P < 0.05) that could exceed the rate of FC delivery and was related to the dialysate FC composition (P < 0.02). There were associated changes in tissue AC output. With dialysate containing 40 mmol acetate/L, AC tissue output was directly related to the dialysate FC composition (P < 0.05). The AC tissue output was less with dialysate containing 3 mmol acetate/L (P < 0.05) but the significant increase with the provision of FC in the dialysate was retained (P < 0.05). Hemodialysis may therefore represent an acute period of relative carnitine deficiency when regeneration of free coenzyme A from acetyl coenzyme A consequent to metabolism of acetate is limited.
Jackson
J M
JM
Department of Renal and Metabolic Medicine, University of Southampton, United Kingdom.
Lee
H A
HA
D000085:Acetates / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D000108:Acetylcarnitine / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002331:Carnitine / Q000097:blood* / Q000493:pharmacokinetics* / Q000502:physiology; D003065:Coenzyme A / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D006435:Renal Dialysis
D000085:Acetates; D000108:Acetylcarnitine; D000105:Acetyl Coenzyme A; D002331:Carnitine; D003065:Coenzyme A