Type I hyperlipoproteinemia caused by lipoprotein lipase defect in lipid-interface recognition was relieved by administration of medium-chain triglyceride.
We have previously reported lipoprotein lipase with a defect of lipid-interface recognition in a patient with type I hyperlipoproteinemia. In this patient, lipoprotein lipase from post-heparin plasma (PHP) hydrolyzed monomeric substrate tributyrin, but scarcely hydrolyzed triolein emulsified with Triton X-100 and that in very-low-density lipoproteins ([VLDL] d < 1.006 g/mL), and did not bind to VLDL. The triglyceride (TG) level of this patient did not decrease to less than 1,000 mg/dL with a low-fat diet (1,400 kcal containing 10 g fat/d). When the patient took 30 g medium-chain TG (MCT) in addition to the 1,400-kcal diet, her serum TG level decreased to 250 mg/dL and her clinical signs improved. The low clearance rate of serum TG with heparin injection improved after intake of MCT. Caproic acid levels were maintained at 1.4% and 2.6% in chylomicrons and VLDL after MCT intake, respectively. The patient's lipoprotein lipase hydrolyzed triolein emulsified with 2% tricaprin at the same rate as that of control lipoprotein lipase. The patient's lipoprotein lipase-catalyzed hydrolyzing rate of triolein in chylomicrons obtained after MCT administration was also enhanced up to 70% of that of control lipoprotein lipase. These findings suggest that hypertriglyceridemia caused by lipoprotein lipase with a defect in lipid-interface recognition could be relieved with the administration of medium-chain TG, and that one of the mechanisms of this effect might be a modification of TG-rich lipoproteins by MCT.
Shirai
K
K
Second Department of Internal Medicine, School of Medicine, Chiba University, Japan.
Kobayashi
J
J
Inadera
H
H
Ohkubo
Y
Y
Mori
S
S
Saito
Y
Y
Yoshida
S
S
D000293:Adolescent; D002250:Carbon Radioisotopes; D002914:Chylomicrons / Q000737:chemistry; D004041:Dietary Fats / Q000008:administration & dosage; D005079:Excipients / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000097:blood; D006801:Humans; D006868:Hydrolysis; D008072:Hyperlipoproteinemia Type I / Q000188:drug therapy*; D007267:Injections; D008049:Lipase / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008071:Lipoprotein Lipase / Q000502:physiology; D008079:Lipoproteins, VLDL / Q000737:chemistry; D008099:Liver / Q000201:enzymology; D017830:Octoxynol; D011092:Polyethylene Glycols; D014280:Triglycerides / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D014304:Triolein
D002250:Carbon Radioisotopes; D002914:Chylomicrons; D004041:Dietary Fats; D005079:Excipients; D005227:Fatty Acids; D008055:Lipids; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D014304:Triolein; D011092:Polyethylene Glycols; D017830:Octoxynol; D006493:Heparin; D008049:Lipase; D008071:Lipoprotein Lipase; C010800:tricaprin