In vivo metabolism of apo A-I and apo A-II in subjects with apo A-I(Lys107-->0) associated with reduced HDL cholesterol and Lp(AI w AII) deficiency

Atherosclerosis. 1997 Feb 10;128(2):213-22. doi: 10.1016/s0021-9150(96)05992-8.


Apolipoprotein A-I (apo A-I) and apolipoprotein A-II (apo A-II) represent 80 90% of the protein content of high density lipoproteins (HDL). Previously we have identified a Finnish family with an apo A-I variant (Lys107-->0) associated with reduced plasma HDL cholesterol level and decreased lipoprotein (Lp)(AI w AII) concentration compared to unaffected family members. To determine the in vivo metabolism of apo A-I and apo A-II in the carriers of apo A-I (Lys107-->0) variant we radioiodinated normal apo A-I with 125I and apo A-II with 131I and compared the kinetic data of two heterozygous apo A-I(Lysl07-->0) patients (HDL cholesterol leves 0.31 and 0.69 mmol/l) to that of eight normolipidemic, healthy control subjects. Plasma radioactivity curves of 125I-labelled normal apo A-I of the patients demonstrated accelerated clearance of apo A-I compared to control subjects. In the two patients the fractional catabolic rates (FCR) of apo A-I were 0.347/day and 0.213/day, respectively, while the mean FCR of apo A-I of the control subjects was 0.151 +/- 0.041/day. Similarly, the plasma decay curves of the 131I-labelled apo A-II showed more rapid clearance of apo A-II in the two patients than in control subjects. The FCR of apo A-II in the two patients were 0.470/day and 0.234/day, while the mean FCR of apo A-II in control subjects was 0.154 +/- 0.029/day. The calculated production rates of apo A-I were similar in patients and in control subjects, and the production rates of apo A-II were significantly higher in patients than in control subjects. Our results show that the Lp(AI w AII) deficiency in patients with the apo A-I(Lys107-->0) is associated with increased fractional catabolic rates of normal apo A-I and apo A-II, while the production rates of these apolipoproteins are normal (apo A-I) or slightly increased (apo A-II).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apolipoprotein A-I / blood*
  • Apolipoprotein A-I / genetics*
  • Apolipoprotein A-II / blood*
  • Cholesterol, HDL / blood*
  • Enzymes / metabolism
  • Female
  • Genetic Variation*
  • Heterozygote
  • Humans
  • Kinetics
  • Lipids / blood
  • Lipolysis
  • Lipoprotein(a) / analogs & derivatives*
  • Lipoprotein(a) / blood
  • Lipoprotein(a) / deficiency*
  • Lipoproteins / blood
  • Male
  • Middle Aged
  • Reference Values


  • Apolipoprotein A-I
  • Apolipoprotein A-II
  • Cholesterol, HDL
  • Enzymes
  • Lipids
  • Lipoprotein(a)
  • Lipoproteins
  • lipoprotein A-I