METABOLISM OF APO(A) AND APOB100 OF LIPOPROTEIN(A) IN WOMEN - EFFECT OF POSTMENOPAUSAL ESTROGEN REPLACEMENT

Citation
Wf. Su et al., METABOLISM OF APO(A) AND APOB100 OF LIPOPROTEIN(A) IN WOMEN - EFFECT OF POSTMENOPAUSAL ESTROGEN REPLACEMENT, The Journal of clinical endocrinology and metabolism, 83(9), 1998, pp. 3267-3276
Citations number
69
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrynology & Metabolism
ISSN journal
0021-972X
Volume
83
Issue
9
Year of publication
1998
Pages
3267 - 3276
Database
ISI
SICI code
0021-972X(1998)83:9<3267:MOAAAO>2.0.ZU;2-Q
Abstract
The metabolism in plasma of apo(a) and apoB100, the major protein comp onents of lipoprotein(a) [Lp(a)], and the mechanism by which estrogen lowers Lp(a) concentration are both not well understood. Estrogen or p lacebo were administered to 12 postmenopausal women in a double-blind cross-over design; and after each treatment, apo(a) and apoB100 in Lp( a) were endogenously labeled by iv trideuterated leucine. After estrog en treatment, mean Lp(a) concentration decreased during estrogen, from 25 mg/dL, by 20% (P < 0.01); and the mean production rate of apo(a) d ecreased, from 0.31 nmol/kg.day, by 34% (P = 0.046). In contrast, the mean fractional catabolic rates of apo(a) were similar, 0.36 vs. 0.31/ day (P = 0.23). In 6 women, the kinetics of apo(a) and apoB100, the tw o major proteins of Lp(a), were studied during estrogen and placebo pe riods. During both periods, the rate of appearance of tracer was simil ar in Lp(a)-apo(a) and Lp(a)-apoB100, as were the resulting metabolic rates and the changes during estrogen treatment. In conclusion, the fi ndings are more compatible with intracellular synthesis of Lp(a) from nascent apo(a) and apoB100 than extracellular assembly from plasma low -density lipoproteins. Reduced flux into plasma of Lp(a), an atherogen ic Lipoprotein, could contribute to the lower cardiovascular disease r ates in women receiving estrogen replacement therapy.