Abstract
Apolipoprotein A-I (apoA-I) participates in transport of plasma cholesterol. Concentrations of apoA-I depend on the balance between production and fractional clearance. To elucidate factors influencing apoA-I levels, accurate estimates of apoA-I turnover rates may be valuable. We describe a method for isolation of autologous apoA-I and its use in turnover studies. Free apoA-I was isolated from high density lipoproteins (HDL) by treatment with guanidine hydrochloride. This free apoA-I was radioiodinated with 131I and injected into eleven subjects simultaneously with HDL labeled with 125I. Plasma die-away curves of free apoA-I (131I) and HDL apoA-I (125I) were compared; fractional clearance rates averaged 0.256 ± 0.019 (SEM) and 0.254 ± 0.017 pools/day, respectively. Although slight differences between the two die-away curves were noted for some of the patients, the differences were relatively small; for the group as a whole, average fractional catabolic rates were not significantly different. Thus, by isolation of autologous apoA-I under the conditions described, free apoA-I seemingly provides a valid method for estimating apoA-I turnover.
Original language | English (US) |
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Pages (from-to) | 867-875 |
Number of pages | 9 |
Journal | Journal of lipid research |
Volume | 32 |
Issue number | 5 |
State | Published - 1991 |
Keywords
- guanidine hydrochloride
- high density lipoprotein
- lipoproteins
- radioiodination
- turnover
ASJC Scopus subject areas
- Biochemistry
- Endocrinology
- Cell Biology