[Does estradiol modify the NO/cGMP system of blood vessels? Studies of the mechanism of cardiovascular protection by estrogen substitution in the postmenopausal period].
The effect of estradiol on the vasodilating NO/cGMP-system has been investigated in vitro and in vivo. Measurements of cGMP were carried out, cGMP values reflecting NO production. The incubation of human leg vein homogenates (n = 15) for 15 min. with estradiol in the concentrations 10(-6) M, 10(-7) M and 10(-8) M showed at 10(-8) a slight increase of the cGMP-concentrations. Due to high variation compass the difference to the control value was not statistically significant. The clinical part of the study included postmenopausal women, 20 were treated with transdermal estradiol patches (TTS, 0.05 mg/die) and 20 with estradiolvalerate orally (2 mg/die). There were 3 drop outs, 1 in the transdermal estrogen group, 2 in the oral estrogen group. In both groups there were no considerable differences in urinary cGMP concentrations. Thus, these results didn't clearly indicate an involvement of the NO/cGMP-system in the cardioprotective effect of an estrogen substitution therapy in postmenopausal women. Since former investigations are indicative of complex interactions of different vasoactive systems and of the requirement of longer treatment periods for an action of estradiol, an effect on the NO/cGMP-system cannot be ruled out.
Sektion für Klinische Pharmakologie in Gynäkologie und Geburtshilfe, Universitäts-Frauenklinik, Tübingen.
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D000279:Administration, Cutaneous; D000284:Administration, Oral; D002318:Cardiovascular Diseases / Q000503:physiopathology / Q000517:prevention & control*; D002979:Climacteric / Q000187:drug effects* / Q000502:physiology; D046508:Culture Techniques; D006152:Cyclic GMP / Q000378:metabolism*; D004958:Estradiol / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000503:physiopathology; D009569:Nitric Oxide / Q000378:metabolism*; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
D009569:Nitric Oxide; D004958:Estradiol; D006152:Cyclic GMP
Beeinflusst Ostradiol das NO/cGMP-System der Gefässe? Untersuchungen zum Mechanismus der kardiovaskulären Protektion durch Ostrogensubstitution in der Postmenopause.