[27- Hydroxycholesterol reverses estradiol induced inhibition of platelet aggregation in postmenopausal women].

Revista medica de Chile

PubMedID: 28394953

Rocha G, Sierralta W, Valladares L. [27- Hydroxycholesterol reverses estradiol induced inhibition of platelet aggregation in postmenopausal women]. Rev Med Chil. 2016;144(11):1377-1381.
BACKGROUND
The decline of estrogen levels increases cardiovascular risk in women. Platelets express estrogen receptors and 17ß-estradiol- (E2) can produce a protective effect on thrombus formation. The hydroxylation of cholesterol generates several sterols and 27-hydroxycholesterol (27HC) predominates in circulation.

AIM
To evaluate the effect of 27HC as an endogenous antagonist of the anti-aggregating properties of E2 in platelets of postmenopausal women.

MATERIAL AND METHODS
Platelet function of postmenopausal women was evaluated ex-vivo. Platelets pre-incubated with 27HC in the presence or absence of E2, were stimulated with collagen. Aggregation was evaluated using turbidimetry using a Chrono-log aggregometer.

RESULTS
Collagen-stimulated platelet aggregation was significantly inhibited by E2. The inhibitory effect of E2 on collagen-stimulated platelet aggregation was significantly reversed in the presence of 27HC.

CONCLUSIONS
The suppressive effect of E2 on platelet aggregation is inhibited by 27HC, which could contribute to increase cardiovascular risk in postmenopausal women.