166

Biochimica et Biophysics Acta, 441(1976) o Elsevier Scientific Publishing Company,

166-169

Amtmdam

- Printed in The Netherlands

BBA Report BBA 51193

UPTAKE OF RADIOLABELED GALACTOSYL-(al+4)-GALACTOSYL(@l-+4)-GLUCOSYLCERAMIDE BY HUMAN SERUM LIPOPROTEINS IN VITRO

J.T.R. CLARKE and J.M. STOLTZ Departmenta of Pediatrics and Biochemistry, Dalhoueie University, and !i%e Atlantic Research Centre for Mental Retardation, Halifax, Nova Scotia B3H 4H7 (Canada) (Received

April 2nd, 1976)

Human serum was exposed to various amounts of [6-3H]galactosyl(al+4)[email protected]+4)-glucosylceramide under standardized conditions in vitro, and the uptake of the lipid by serum lipoproteins was determined. Of the bound glycolipid, 2% was isolated with very low density, 24% with low density-, 47% with high density lipoproteins and 27% with the ultracentrifugal residue. The distribution was different from the distribution of endogenous [email protected], indicating that the glycolipid is probably an integral part of the lipoprotein complexes in vivo.

In patients with Fabry’s disease, an X-linked disorder of glycosphingolipid metabolism, triglycosylceramide (galactosyl-(al+4)-galactosyl-(@l-+4)glucosylceramide) accumulates in the walls of small arteries, the kidneys and other tissues [2]. Unlike in other sphingolipid storage diseases, accumulation of lipid in the central nervous system and reticuloendothelial system is negligible. The fact that plasma triglycosylceramide levels in patients with this disease are elevated 3-5 times above normal [3] sugges’tsthat the accumulation of the lipid in vascular tissue may occur by sequestration from the circulation. If this is the case, the rate of deposition of triglycosylceramide may be influenced by the manner in which it is transported in the circulation. Moreover, it may be possible to modify the rate of triglycosylceramide deposition, and thus the rate of progression of the disease, by modifying the transport system. Previous studies have shown that triglycosylceramide is transported bound Abbrevi8thu: VLDL. very low dmdty ~otmtein (d

Uptake of radiolabeled galactosyl-(alpha1 goes to 4)-galactosyl-(beta1 goes to 4)-glucosylceramide by human serum lipoproteins in vitro.

166 Biochimica et Biophysics Acta, 441(1976) o Elsevier Scientific Publishing Company, 166-169 Amtmdam - Printed in The Netherlands BBA Report BB...
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