Effect of lipoprotein-X on lipid metabolism in rat kidney.

Abstract

Lipoprotein-X (Lp-X) is found in the plasma of patients with familial lecithin: cholesterol acyltransferase (LCAT) deficiency syndromes. The majority of the patients with this disorder develop progressive glomerulosclerosis. In this study, the effect of Lp-X on lipid metabolism in perfused rat kidney was investigated. Lp-X was isolated from plasma of patients with familial LCAT deficiency by sequential ultracentrifugation and gel filtration column chromatography. Rat kidneys were perfused for 1-2 h with Krebs-Henseleit buffer containing 20 microM [1-(14)C]acetate or 20 microM [Me-3H]choline. In the presence of Lp-X, no significant difference in the incorporation of radioactivity into triglycerides, cholesterol, phosphocholine, CDP-choline and sphingomyelin was observed. However, incorporation of radioactivity into cholesteryl esters and phosphatidylcholine was significantly elevated in Lp-X perfused kidneys. The contents of cholesterol, cholesteryl esters and phosphatidylcholine were also significantly increased in Lp-X perfused kidneys. The increase in lipid content in the Lp-X perfused kidney is attributed to the direct deposition of Lp-X lipids into the organ. The increase in the labelling of cholesteryl esters was attributed to the increase of available substrate (cholesterol) for the acyl-CoA:cholesterol acyltransferase (ACAT) reaction. The increase in phosphatidylcholine labelling was caused by a reduced turnover of the newly synthesized labelled phosphatidylcholine during Lp-X perfusion.

• Authors: K O, M Ly, D Z Fang, J Frohlich, P C Choy
• Journal: Molecular and cellular biochemistry (Mol Cell Biochem) Vol. 173 Issue 1-2 Pg. 17-24 (Aug 1997) ISSN: 0300-8177 [Print] Netherlands
• PMID: 9278250 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Acetates
• Lipids
• Lipoprotein-X
• Lipoproteins
• 1-Acylglycerophosphocholine O-Acyltransferase
• Phospholipases A
• Choline

Topics

• 1-Acylglycerophosphocholine O-Acyltransferase (drug effects, metabolism)
• Acetates (metabolism)
• Animals
• Choline (metabolism)
• Humans
• Kidney (enzymology, metabolism, ultrastructure)
• Lecithin Cholesterol Acyltransferase Deficiency (metabolism)
• Lipid Metabolism
• Lipids (analysis)
• Lipoprotein-X (administration & dosage, pharmacology)
• Lipoproteins (pharmacology)
• Male
• Microsomes (enzymology)
• Perfusion
• Phospholipases A (drug effects, metabolism)
• Rats
• Rats, Sprague-Dawley