There is evidence that
estrogen is associated with a reduction on
cardiovascular disease risk through inhibition of platelet aggregation and action on vascular function. The process of haemostasis can also be affected by
adenine nucleotides and
adenosine. Consequently, regulation of
enzymes that hydrolyze these
nucleotides in the bloodstream is essential in the modulation of the processes of platelet aggregation, vasodilatation and coronary flow.
Ecto-ATP diphosphohydrolase and
ecto-5'-nucleotidase from platelets are
enzymes related to
nucleotide hydrolysis. In the present study, we examined the effect of
ovariectomy (OVX) and
estradiol replacement
therapy (ER) on the activity of the
enzymes that degrade
adenine nucleotides in platelets of female rats. The OVX group significantly decrease the hydrolysis of
ATP,
ADP and
AMP by 42, 52 and 29.3%, respectively, when compared to a control group. ER did not reverse the inhibition of
nucleotide hydrolysis observed in OVX rats. Our findings indicate that hormonal deprivation affects
ATP,
ADP and
AMP hydrolysis by platelets and consequently the level of these
nucleotides and
adenosine in the circulation. Since,
ADP is the most important platelet agonist and recruiting agent present in the microenvironment of the
thrombus, our findings was contribute to a better comprehension of the cardiovascular complications described in alterations of sexual hormonal status.