Protective effects of 17 beta-estradiol on endothelial function injured by oxidized low-density lipoproteins.
OBJECTIVE
To test the protective effects of 17 beta-estradiol against endothelial cell damages due to oxidized low-density lipoproteins (LDL) and lysophosphatidylcholine (LPC), a principal component of oxidized LDL.


METHODS
After the tension was increased by phenylephrine, the effects of oxidized LDL or LPC on the vasorelaxation responses to acetylcholine (ACh) were investigated in the isolated rabbit thoracic aortas.


RESULTS
17 beta-Estradiol attenuated the inhibition of vasorelaxation responses to ACh by oxidized LDL or LPC in a concentration-dependent manner. However, the protective effect of 17 beta-estradiol was partially attenuated by indometacin (10 mumol.L-1), a cyclooxygenase inhibitor.


CONCLUSIONS
17 beta-Estradiol possesses protective effects on the endothelium against injury elicited by oxidized LDL or LPC, which may be related to its stimulation of epoprostenol production.
Peng
C F
CF
Department of Pharmacology, Hunan Medical University, Changsha, China.
Li
Y J
YJ
Deng
H W
HW
Xiong
X M
XM
D000818:Animals; D001013:Aorta, Thoracic; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects*; D004958:Estradiol / Q000494:pharmacology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008075:Lipoproteins, HDL / Q000037:antagonists & inhibitors*; D008244:Lysophosphatidylcholines / Q000037:antagonists & inhibitors*; D008297:Male; D011817:Rabbits; D014664:Vasodilation / Q000187:drug effects*
D016861:Cyclooxygenase Inhibitors; D008075:Lipoproteins, HDL; D008244:Lysophosphatidylcholines; D004958:Estradiol; D007213:Indomethacin