title: Increased low-density-lipoprotein catabolism in myeloproliferative disorders.
abstract: Hypocholesterolemia reported in patients with myeloproliferative disorders prompted our investigation of lipoprotein metabolism in these patients. The production and fractional catabolic rates of very-low-density lipoprotein (VLDL) apoprotein-B were measured using 131I-VLDL; those of VLDL triglyceride, using 3H-glycerol; and those of low-density lipoprotein (LDL) apoprotein-B, using 125I-LDL. Plasma total and LDL cholesterol levels (mean +/- SD) were significantly reduced in seven patients with myeloproliferative diseases, compared to five normal subjects (93.1 +/- 20.3 mg/dL versus 166.8 +/- 24.6 mg/dL and 50.3 +/- 14.8 mg/dL versus 107 +/- 20.8 mg/dL, respectively). The production rates of VLDL apoprotein-B and VLDL triglyceride were normal in the patients. The fractional catabolic rate of LDL apoprotein-B was increased in the patients with myeloproliferative diseases (0.89 +/- 0.32/d versus 0.52 +/- 0.10/d; p less than 0.05); this increased rate was associated with reduced plasma LDL apoprotein-B levels (41.7 +/- 7.1 mg/dL versus 57.0 +/- 11.3 mg/dL; p less than 0.05) despite normal or elevated LDL apoprotein-B production (16.7 +/- 5.3 mg/kg body weight . d versus 12.9 +/- 1.2 mg/kg body weight . d). The site (or sites) of increased LDL catabolism in these hypocholesterolemic patients with myeloproliferative disorders is under investigation.
mesh_terms: D000328:Adult; D000368:Aged; D001053:Apolipoproteins / Q000097:blood; D001055:Apolipoproteins B; D001711:Biotransformation; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D001053:Apolipoproteins; D001055:Apolipoproteins B; D008078:Cholesterol, LDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D002784:Cholesterol