Reagent for the quantitative in vitro determination of platelet function triggered by adenosine diphosphate and Prostaglandin E1 Reagent (in conjunction with reagent ADPtest). For the assessment of ADPtest HS (high sensitivity) and of positive (i.e. abnormal) controls of the ADPtest. The addition of 20 μL PGE1 to the ADPtest induces a moderate inhibition of platelet activation in healthy normal blood samples, but a significant increase of sensitivity of the ADPtest to the platelet inhibition by clopidogrel. Therefore this modified assay is named ADPtest HS (high sensitivity).
The addition of 50 μL PGE1 into the ADPtest induces a strong inhibition of ADP induced aggregation (positive control for ADPtest).
Adenosine diphosphate (ADP) induced platelet aggregation is achieved through binding of the ADP molecule to purinergic receptors, P2Y1 and P2Y12 on platelet membranes. The P2Y1 receptor is associated with the mobilization of calcium stores and the initiation of ADP induced aggregation whereas the P2Y12 is the more important of the two receptors and is attributed with the amplification and completion of the aggregation process. Stimulation of the P2Y1 receptor causes a downstream inhibition of cyclic adenosine monophosphate (cAMP), thus facilitating the activation process.
The P2Y12 receptor is also responsible for the sustained aggregation effect of ADP stimulation.Prostaglandin E1 Reagent (PGE1) increases cAMP concentrations by stimulating adenyl cyclase activity in platelets; the increase in cAMP inhibits calcium mobilization and platelet aggregation induced by P2Y1 receptor activation. The addition of PGE1 to a blood sample can reduce the platelet activation by the P2Y1 receptor in a concentration dependent manner.
This effect enables the more sensitive evaluation of substances that affect platelet aggregation through P2Y12 receptor binding.
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