Effects of estrogen and progesterone on platelet-activating factor acetylhydrolase activity in ovariectomised rats.
OBJECTIVE
To evaluate the effect of estrogen and progesterone on plasma platelet-activating factor acetylhydrolase (PAF-AH) activity in ovariectomized rats.


METHODS
Plasma PAF-AH activity was examined in ovariectomized rats treated with 17 alpha-ethynylestradiol (0.25 mg/kg; 6 days) or medroxyprogesterone (50 mg/kg; 6 days). The intra- and inter-assay coefficients of variation for plasma PAF-AH activity were 2.5% and 4.4%, respectively. Plasma lipoprotein profiles on day 5 were determined with commercially available kits.


RESULTS
Ovariectomized rats showed no significant change in plasma PAF-AH activity over a 14 day period. Estrogen decreased the PAF-AH activity up to 85%, and progesterone increased PAF-AH activity up to 44% in ovariectomized rats. There was a positive correlation between plasma PAF-AH activity and high density lipoprotein cholesterol (r = 0.96, p < 0.001).


CONCLUSIONS
These data suggest that estrogen and progesterone exert an effect on plasma PAF-AH activity in ovariectomized rats, possibly via high density lipoprotein cholesterol.
Ohshige
A
A
Department of Obstetrics and Gynecology, Kumamoto University School of Medicine, Japan.
Ito
M
M
Koyama
H
H
Maeda
T
T
Yoshimura
T
T
Okamura
H
H
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000818:Animals; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D007700:Kinetics; D016018:Least-Squares Analysis; D008074:Lipoproteins / Q000097:blood; D008525:Medroxyprogesterone / Q000494:pharmacology*; D010052:Ovariectomy; D010741:Phospholipases A / Q000097:blood* / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008074:Lipoproteins; D014280:Triglycerides; D004997:Ethinyl Estradiol; D002784:Cholesterol; D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D008525:Medroxyprogesterone