Influence of plasma phytanic acid levels in Refsum's disease on the behaviour of the erythrocyte membrane sodium-lithium countertransporter
Abnormal behaviour of the erythrocyte membrane sodium-lithium countertransporter (SLC) is associated with plasma triglyceride concentrations. Refsum's disease is characterized by progressive neurological dysfunction and accumulation of phytanic acid, an isoprenoid fatty acid, in fat-containing tissues. Methods
This study explored the effects of plasma phytanic acid on SLC kinetics in nine Caucasian patients with Refsum's disease and in age- and sex-matched Caucasian control subjects. Results
A dose-dependent association was seen between countertransporter maximal velocity and phytanic acid content of low-density lipoprotein (LDL)-cholesterol (r = -0.61, r = -0.65 respectively; P = 0.05, P = 0.04) and high-density lipoprotein (HDL)-cholesterol (r = - 0.81, - 0.82 respectively; P = 0.005, P = 0.003). No significant association was seen with the sodium affinity of the transporter (r = - 0.44, P = 0.20, for LDL; and - 0.43, P = 0.21, for high-density lipoprotein). Conclusion
These findings suggest that phytanic acid may alter the behaviour of the sodium-lithium countertransporter.
Document Type: Research Article
Affiliations: 1: Senior Lecturer in Chemical Pathology, St Thomas Hospital, London, UK 2: Department of Cardiovascular Medicine, Charing Cross Hospital, London, UK 3: Department of Chemical Pathology, St Thomas Hospital, London, UK 4: Department of Clinical Pharmacology and Therapeutics, Chelsea & Westminster Hospital, London, UK 5: Department of Medicine, Chelsea & Westminster Hospital, London, UK 6: Consultant Physician and Neurologist, Chelsea & Westminster Hospital, London, UK
Publication date: 1998-04-01