| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ORIGINAL RESEARCH |
From the Department of Obstetrics and Gynecology, Kochi Medical School, Kochi, Japan.
Address reprint requests to: Akihiko Wakatsuki, MD Department of Obstetrics and Gynecology Kochi Medical School Oko-cho, Nankoku Kochi, 783-8505 Japan
Objective: To investigate the effects of estrogen on lipid transfer reactions and lipid composition of low-density lipoprotein (LDL) particles in postmenopausal women.
Methods: Twelve postmenopausal women were treated with conjugated equine estrogen, 0.625 mg daily, for 3 months. Plasma concentrations of total cholesterol, triglyceride, and high-density lipoprotein (HDL) cholesterol were measured before and after therapy. We also determined the amount of total, free, and esterified cholesterol, triglyceride, and apolipoprotein B in LDL. To evaluate lipid transfer reactions, plasma samples were incubated at 37C for 24 hours, and replacement of cholesteryl ester by triglyceride in LDL particles was analyzed. Cholesterol and triglyceride concentrations were measured enzymatically. Apolipoprotein B concentrations were determined by an immunoturbidimetric assay.
Results: Estrogen significantly reduced the plasma levels of total cholesterol and significantly increased those of triglyceride and HDL cholesterol. The ratio of cholesteryl ester to apolipoprotein B was reduced significantly, whereas the ratio of triglyceride to apolipoprotein B increased significantly after estrogen treatment. Both before and after estrogen treatment, incubation of plasma induced a significant increase in the ratio of LDL-triglyceride to apolipoprotein B with a concomitant decrease in the ratio of LDL–cholesteryl ester to apolipoprotein B. Incubation-induced changes in these ratios were significantly enhanced by estrogen therapy. The plasma concentration of triglyceride was correlated positively with incubation-induced changes in the ratio of LDL-triglyceride to apolipoprotein B (r = .83, P < .001) and correlated negatively with changes in the ratio of LDL–cholesteryl ester to apolipoprotein B (r = -.61, P < .01).
Conclusion: Estrogen-induced increase in the plasma level of triglyceride may enhance lipid transfer reactions, resulting in triglyceride-rich and cholesteryl ester-poor LDL particles.
This article has been cited by other articles:
|
|
 |
|
  A. Wakatsuki, Y. Okatani, N. Ikenoue, K. Shinohara, K. Watanabe, and T. Fukaya Effect of Lower Dose of Oral Conjugated Equine Estrogen on Size and Oxidative Susceptibility of Low-Density Lipoprotein Particles in Postmenopausal Women Circulation, August 19, 2003; 108(7): 808 - 813. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Wakatsuki, Y. Ogawa, T. Saibara, Y. Okatani, and T. Fukaya Size and Oxidative Susceptibility of Low-Density Lipoprotein Particles in Breast Cancer Patients with Tamoxifen-Induced Fatty Liver J. Clin. Endocrinol. Metab., August 1, 2002; 87(8): 3676 - 3681. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. WAKATSUKI, N. IKENOUE, Y. OKATANI, K. SHINOHARA, K. WATANABE, and T. FUKAYA Lipolytic Enzyme Effect on Small Low-Density Lipoprotein Particles in Women Treated With Estrogen Obstet. Gynecol., March 1, 2001; 97(3): 333 - 337. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Wakatsuki, N. Ikenoue, Y. Okatani, and T. Fukaya Estrogen-induced small low density lipoprotein particles may be atherogenic in postmenopausal women J. Am. Coll. Cardiol., February 1, 2001; 37(2): 425 - 430. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. A. LUCIANO, B. E. MILLER, M. J. SCHOENENFELD, and R. J. SCHASER Effects of Estrone Sulfate Alone or With Medroxyprogesterone Acetate on Serum Lipoprotein Levels in Postmenopausal Women Obstet. Gynecol., January 1, 2001; 97(1): 101 - 108. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
